a 1 =−4a, start subscript, 1, end subscript, equals, minus, 4 a_i = a_{i - 1} \cdot 2a i =a i−1 ⋅2

Answer:

678.672cm^2

Step-by-step explanation:

Given data

A cone is described by the length and radius

l=19cm

r=8cm

The formula for the surface area of the cone is

T.S.A=πrl+πr^2

Substitute

T.S.A=3.142*8*19+3.142*8^2

T.S.A=477.584+201.088

T.S.A=678.672

Hence the surface area is

678.672cm^2

Answer:

A = 139.25 cm^2

Step-by-step explanation:

The composite shape is made up of a square with side 10 cm and a semicircle with diameter 10 cm. The area of the composite shape is the sum of the two areas. The diameter of the semicircle is the side of the square, and the radius of the circle is half of the diameter.

A = s^2 + (1/2)(pi)r^2

r = d/2 = s/2

A = (10 cm)^2 + (1/2)(3.14)(10 cm/2)^2

A = 100 cm^2 + (1/2)(3.14)(25 cm^2)

A = 139.25 cm^2

Answer:

A.

it’s a because i just got it right on the test

Answer:

its A cause i got it right

Step-by-step explanation:

for the boys

Answer:

I think the answer would be Y=-2X+5

Hope it helps you *^*

The meaurment of the ∠D= 40°, ∠A=140°, ∠B=130.

Given in the image we can see ∠C and ∠ D is an acute angle and the value of ∠C is 50° so ∠D must be 40° according to the image.

The sum of the angle on the same side of trapezoid is equal to 180°. so ∠A+D and ∠C+∠B= 180°. ∠A+40°=180°. after substracting the value ∠A will be 140° and by same method ∠B+50°=180°. we will get ∠B=130°.

Therefore ∠D= 40°, ∠A= 140°, ∠B= 130°.

To learn more about Trapezium

visit-: https://brainly.com/question/

21400

Answer:

Step-by-step explanation:

To be a function x can't repeat with a different y so in a every element of x is mapped to a different y so it is a function.

For choice B, -4 is paired with both 7 and 8 so it is not a function.

Choice C is a function since each x is paired with a different y.

(a) All the elements of S are : S = {RR, RB, BR, BB},

(b) Elements in event A are {RB and BR},

(c) The probability of "event-A", which is the person drawing one "red-ball" and one "black-ball", is 1/2.

Part (a) : The "sample-space" (S) consists of all possible outcomes when drawing two balls with replacement. In this case, there are four possible outcomes : S = {RR, RB, BR, BB},

Part (b) : The "event-A" represents the person drawing one red-ball and one black-ball. The elements in event A are {RB and BR},

Part (c) : To calculate the probability P(A), we need to determine the ratio of favorable outcomes (elements in A) to the total number of possible outcomes (elements in S).

P(A) can be written as : (Number of favorable outcomes)/(Total number of possible outcomes),

Substituting the values from part(a) and part(b),

We get,

P(A) = 2/4

P(A) = 1/2

Therefore, the required probability is 1/2.

Learn more about Sample Space here

https://brainly.com/question/10558484

#SPJ4

Answer:

Step-by-step explanation:

Lets break the 2 boxes apart so you have 4*4*3 =48 and then you have 10*3*2 = 60

60 +48 = 108

108cm^3

Answer:

lateral area = side area = (10 x 6 x 2) + (14 x 10 x 2) = 400 in²

total surface area = lateral area + top & bottom area = 400 + (14 x 6 x 2) = 568 in²

(a) In step 3, the variable X will be entered into the model.

(b) The inclusion of all four variables in the final model does not guarantee their significance; further analysis is needed to determine their individual significance.

In step 3 of the forward selection procedure, the variable X will be entered into the model. This means that after step 2, the model includes variables X and X, and in step 3, the variable X is added.

No, the fact that all four independent variables are entered in the final model does not necessarily mean that all of them are significant. The forward selection procedure is a stepwise approach that adds variables to the model based on certain criteria, typically using a significance level or a criterion such as the increase in the adjusted R-squared.

However, the final model with all four variables entered does indicate that these variables have met the criteria for inclusion in the model based on the stepwise procedure. It suggests that each variable contributes to the prediction of the dependent variable Y, after accounting for the variables that were already in the model.

To determine the significance of each variable in the final model, further statistical analysis, such as hypothesis testing or examining the p-values of the coefficients, is required. These tests can assess the individual significance of each variable and help determine if they have a statistically significant relationship with the dependent variable.

Learn more about regression analysis here, https://brainly.com/question/28178214

#SPJ11

The alternate form of the polar decomposition of `A` is given by `A = PW`, where `W` is a positive semidefinite Hermitian matrix and `P` is a positive semidefinite Hermitian matrix.

Let `A` be a square matrix. Prove an alternate form of the polar decomposition for `A`.For a given square matrix `A`, the polar decomposition of `A` is a factorization of `A` into the product of a unitary matrix `U` and a positive semi-definite Hermitian matrix `P`. This polar decomposition of `A` can be given by `A = UP` or `A = PU*`, where `U` is the unitary matrix and `P` is a positive semidefinite matrix such that `P = (AA*)^(1/2)` or `P = (A*A)^(1/2)`.

The alternate form of the polar decomposition of `A` is given by `A = PW`, where `W = P^(1/2)U P^(1/2)` and `P` is a positive semidefinite matrix.Let `A = UP` be the polar decomposition of `A`, where `U` is unitary and `P` is positive semi-definite Hermitian. Then `P = A(A*)^(1/2)` and `U = P^(-1)A`. Let `W = P^(1/2)U P^(1/2)` and `W* = P^(1/2)U* P^(1/2)`. Since `U` is unitary, we have `U* = U^(-1)`. Hence `W* = P^(1/2)U^(-1) P^(1/2)`.Multiplying `UP` by `P^(1/2)`, we get `UP^(1/2) = P^(1/2)U P`. Multiplying both sides of the equation by `P^(1/2)` on the right, we get `UP^(1/2)P^(1/2) = P^(1/2)U P P^(1/2)` or `UP = P^(1/2)U P^(1/2)P^(1/2)` or `UP = P^(1/2)U P^(1/2)` or `U = P^(-1/2)W P^(1/2)`.

Substituting the value of `U` in `A = UP`, we get `A = P^(-1/2)W P^(1/2)P`. Since `P` is positive semi-definite, `P = (P^(1/2))^2` is a Hermitian matrix. Therefore, `W = P^(1/2)U P^(1/2)` is a Hermitian matrix and is positive semi-definite. Thus, we have `A = PW` where `W = P^(1/2)U P^(1/2)` is a positive semidefinite Hermitian matrix. Hence, the alternate form of the polar decomposition of `A` is given by `A = PW`, where `W` is a positive semidefinite Hermitian matrix and `P` is a positive semidefinite Hermitian matrix.

Learn more about  Hermitian matrix here:

https://brainly.com/question/31432979

#SPJ11

Answer:

960

Step-by-step explanation:

it says use 3 for pi, so you plug the values into given equation

V = 3·(4)²·20

r is 4 because it is half of 8.

Then multiply

3·16·20 = 48·20 = 960

Answer:

960 cm

Step-by-step explanation:

8/2 = 4 (radius)

3 (since we're using 3 for pi) * 4^2 * 20

3 * 16 * 20

48 * 20

= 960 cm

I hope this helps heh :)

The researcher wrote that, because she had a small sample, she thought she had made a Type 1 error.

The correct assessment of what the researcher wrote is: She could be right about making the Type 1 error, but there is no way of knowing for sure. Here's why:In statistics, a Type I error occurs when a null hypothesis that is true is incorrectly rejected. The probability of a Type I error occurring is referred to as the level of significance.

If a researcher states that she did not reject her null hypothesis but believes she may have made a Type I error due to a small sample size, it is possible that she is correct. However, since she did not reject the null hypothesis, it is impossible to know for sure whether a Type I error occurred. Hence, the correct assessment of what the researcher wrote is: She could be right about making the Type 1 error, but there is no way of knowing for sure.

To know more about statistics refer to:

https://brainly.com/question/27342429

#SPJ11

The compound will be completely used up in the reaction chamber after 60 minutes.

In the given chemical reaction, 20 units of a compound are injected into the reaction chamber every 30 minutes. Within that 30-minute period, 50% of the compound is used up in the chemical process. This means that after 30 minutes, half of the compound has reacted and only 10 units remain in the chamber.

After another 30 minutes, another 20 units are injected, making a total of 30 units in the chamber. However, within this 30-minute period, 50% of the compound is again used up. This results in 15 units being consumed, leaving only 15 units in the chamber.

Following this pattern, we can see that after each 30-minute interval, the number of units remaining in the chamber is halved. Starting with 20 units, after the first 30 minutes, we have 10 units, and after the second 30 minutes, we have 5 units.

Therefore, it can be inferred that after 60 minutes (two 30-minute intervals), the compound will be completely used up in the reaction chamber. No units of the compound will be left.

Learn more about Compound

brainly.com/question/24972577

#SPJ11

(a) The number of football boots XYZ Clothing needs to sell to break even can be found by solving the quadratic equation.

(b) To maximize profit, XYZ Clothing needs to sell 1120 football boots.

(c) Plotting relevant points on a graph, we can sketch XYZ Clothing's profit function, indicating important points.

(a) To find the number of football boots XYZ Clothing needs to sell to break even, we set the profit function equal to zero:

Profit = Revenue - Cost

Since the revenue is given as $120 per football boot and the cost function is provided as C(x) = 3,000 + 8x + 0.1x^2, the profit function is:

Profit = 120x - (3,000 + 8x + 0.1x^2)

Setting the profit function equal to zero, we have:

0 = 120x - (3,000 + 8x + 0.1x^2)

Simplifying the equation, we get:

0 = 112x - 0.1x^2 - 3,000

To find the number of football boots needed to break even, we solve the quadratic equation:

0.1x^2 - 112x + 3,000 = 0

Solving this equation will give us the value of x, which represents the number of football boots XYZ Clothing needs to sell to break even.

(b) To find the number of football boots XYZ Clothing needs to sell to maximize profit, we need to determine the vertex of the profit function. The profit function is the same as in part (a):

Profit = 120x - (3,000 + 8x + 0.1x^2)

To find the vertex, we can use the formula x = -b/2a, where a = 0.1 and b = 112.

x = -(-112) / (2 * 0.1)

x = 1120

So, XYZ Clothing needs to sell 1120 football boots to maximize profit.

(c) To sketch the profit function on a pair of axes, we can plot the points that are relevant to the problem. We know that the profit function is given by:

Profit = 120x - (3,000 + 8x + 0.1x^2)

We can plot the following points:

Breakeven point: (x, 0) where x is the number of football boots needed to break even.

Maximum profit point: (1120, Profit(1120)) where Profit(1120) is the maximum profit obtained when 1120 football boots are sold.

Additionally, we can plot a few more points to get an idea of the shape of the profit function.

By connecting these points, we can sketch the profit function on the axes, indicating the relevant points and labeling them accordingly.

To learn more about quadratic equations visit : https://brainly.com/question/1214333

#SPJ11

Answer:

Hey I have the answer in a link

Look down For link!

Cmon half way there

jkjk

First part (tip amount)

$6.26

Second part (Total bill)

$41.04

Step-by-step explanation:

Well to find the percentage of a number, convert the percent into a decimal which is basically moving the decimal place 2 places to the left. THen you multiply that amount by the original number an din this case you would get 6.2604. You round that to the nearest penny (or hundreths) and you;d get $6.26. Thats the first part

The second part is simple, you add the tip with the total bill and you would get $41.04.

The correct answer is there are 12 customers who are older than 45.

To determine how many customers were older than 45, we need to examine the values in the stem-and-leaf plot that are greater than 45.

Looking at the plot, we can see that the stem values range from 1 to 7. However, the stem values 8 and 9 are missing, so there are no customers with ages starting from 80 to 99.

For the stem values 1, 2, 3, 4, 5, 6, and 7, we can count the number of leaf values that are greater than 5.

Stem 1: There are no leaf values greater than 5.

Stem 2: There are 3 leaf values greater than 5 (6, 6, 8).

Stem 3: There are 4 leaf values greater than 5 (6, 7).

Stem 4: There are 3 leaf values greater than 5 (8).

Stem 5: There are 2 leaf values greater than 5 (6).

Stem 6: There are 0 leaf values greater than 5.

Stem 7: There are 0 leaf values greater than 5.

Adding up the counts for each stem, we get:

0 + 3 + 4 + 3 + 2 + 0 + 0 = 12

Therefore, there are 12 customers who are older than 45.

know more about stem and leaf plot,

https://brainly.com/question/32053953

#SPJ11

To determine how long it would take for the worker to assemble 200 computers, we need to consider the rate at which the worker assembles computers and the total number of computers to be assembled.

Given that the worker can assemble 8 computers per hour, we can set up a proportion to find the time required:

8 computers / 1 hour = 200 computers / x hours

Cross-multiplying and solving for x, we get:

8x = 200

x = 200 / 8

x = 25

Therefore, it would take the worker 25 hours to assemble 200 computers. The correct answer is option (C) 25 h.

To know more about time and rate problems click here: brainly.com/question/29715765

#SPJ11

The y-intercept is -5 and as the x-values increase, the y-values also increase in this graph of the line. which is the correct answer would be options (A) and (D).

A graph can be defined as a pictorial representation or a diagram that represents data or values.

What is the equation of a line?

The general equation of a line is y = mx + c

where m is the slope of the line and c is the intercept.

A linear equation is defined as an equation in which the highest power of the variable is always one.

We have been given that function of the line as

y = 3x - 5

We need to determine the y-intercept.

The y-intercept is at x = 0, y = -5

And the x-intercept is at y = 0, x = 5/3

Here In this graph of the given function as the x-values increase, the y-values also increase.

Therefore, the correct answer would be options (A) and (D).

Learn more about the lines here:

brainly.com/question/2263981

#SPJ2

The conclusion is that there is evidence to warrant rejection of the claim that the standard deviation of men's pulse rates is equal to 10 beats per minute.

a. Null and alternative hypotheses Null hypothesis (H0): The standard deviation of men’s pulse rates is equal to 10 beats per minute.H0: σ = 10Alternative hypothesis (Ha): The standard deviation of men’s pulse rates is not equal to 10 beats per minute.

Ha: σ ≠ 10b. Calculation of test statistic The test statistic for the standard deviation is calculated as:  \[χ^2 = \frac{(n-1)S^2}{σ^2}\]Where n = sample size, S = sample standard deviation, and σ = hypothesized standard deviation. Substituting the values,  \[χ^2 = \frac{(36-1)(64)^2}{(10)^2}\]  \[χ^2 = 1322.56\]

c. Calculation of P-value We can use the chi-square distribution table to find the P-value. At a significance level of 0.10 and 35 degrees of freedom (36-1), the critical values are 19.337 and 52.018.

Since the test statistic value (χ2) of 1322.56 is greater than 52.018, the P-value is less than 0.10. Therefore, we reject the null hypothesis and conclude that the standard deviation of men’s pulse rates is not equal to 10 beats per minute.

Since it is a two-tailed test, we divide the significance level by 2. The P-value for the test is P = 0.000.  Therefore, the P-value is less than the level of significance (0.10).

d. Conclusion Since the P-value is less than the level of significance, we reject the null hypothesis. Hence, there is evidence to support the claim that the standard deviation of men's pulse rates is not equal to 10 beats per minute.

Therefore, the conclusion is that there is evidence to warrant rejection of the claim that the standard deviation of men's pulse rates is equal to 10 beats per minute.

For more such questions on standard deviation

https://brainly.com/question/475676

#SPJ8

Answer:

Dad = 47, Mom = 39, Fritz = 11, Erika = 15 and Adele = 4

Step-by-step explanation:

Let M = Mom's age, D = Dad's age, F = Fritz's age, A = Adele's age and E = Erika's age.

Given that

1) Mom is 8 years younger than Dad, we have D = M + 8   (1)

2) Dad is 2 times as old as Fritz. D = 2F   (2)

3) Adele is 4 years old. A = 4     (3)

4) Fritz's age plus Adele's age equals Erika's age. F + A = E   (4)

5) Mom was 24 when Erika was born. M = E + 24    (5)

6) In 9 years, Mom will be twice as old as Erika will be. M + 9 = 2(E + 9)   (6)

Substituting (5) into (6), we have

E + 24 + 9 = 2(E + 9)

E + 33 = 2E + 18

subtracting E from both sides, we have

2E - E + 18 = 33 + E - E

E + 18 = 33

subtracting 18 from both sides, we have

E + 18 - 18 = 33 - 18

E = 15

M = 15 + 24 = 15 + 24 = 39

From (4) F = E - A = 15 - 4 = 11

From (1) D = M + 8 = 39 + 8 = 47

So, their ages are Dad = 47, Mom = 39, Fritz = 11, Erika = 15 and Adele = 4

Let X be a continuous random variable with probability density function f. We say that X is symmetric about a if for all x,

P(X ≥ a+x)=P(X ≤ a-x).

(a) f(a - x) = f(a + x) if and only if X is symmetric about a.

(b) X is symmetric about a if and only if f(x) = f(2a - x) for all x.

(c) X and Y are symmetric about 3.

(a) To prove that X is symmetric about a if and only if for all x, we have f(a - x) = f(a + x).

Proof: P(X ≥ a+x) = P(X ≤ a-x) ...(1)

Given X is a continuous random variable with probability density function f.

Let F denote the cumulative distribution function of X.

Then, F(x) = P(X ≤ x).

We can now re-write equation (1) as follows: 1-F(a+x) = F(a-x) ... (2).

Taking the derivative of both sides of equation (2) with respect to x, we get: d/dx(1-F(a+x))= d/dx(F(a-x)) ... (3).

Differentiating the LHS of equation (3) using the chain rule, we obtain:- f(a+x) = -d/dx(F(a+x)) ... (4).

Differentiating the RHS of equation (3) using the chain rule, we obtain: f(a-x) = d/dx(F(a-x)) ... (5).

Combining equations (4) and (5), we get: f(a+x) = f(a-x).

Hence, we can conclude that X is symmetric about a if and only if for all x, we have f(a - x) = f(a + x).

Answer: (a) f(a - x) = f(a + x) if and only if X is symmetric about a.

(b) To show that X is symmetric about a if and only if f(x) = f(2a - x) for all x.

Proof: X is symmetric about a if and only if for all x, we have f(a - x) = f(a + x).

Hence, it follows that: f(a + (2a - x)) = f(a - (2a - x)) ... (6).

Simplifying equation (6), we obtain: f(2a - x) = f(x).

Therefore, X is symmetric about a if and only if f(x) = f(2a - x) for all x.

Answer: (b) X is symmetric about a if and only if f(x) = f(2a - x) for all x.

(c) Let X be a continuous random variable with probability density function f(x) = [1 / √(2phi)] e^-(x-3)²/2, x E R, and Y be a continuous random variable with probability density function g(x) = 1 / phi [1 + (x-1)²], x E R.

Find the points about which X and Y are symmetric.

The probability density function of a symmetric random variable X about a is f(x) = f(2a - x).

Therefore, if X is symmetric about a, then we have: f(x) = f(2a - x) ...(7).

Comparing the probability density function of X to the given probability density function f(x), we can observe that X is symmetric about a = 3.

Therefore, we can find the points about which X and Y are symmetric by solving the following equation: g(x) = f(2a - x) ... (8).

Substituting the value of a in equation (8), we get:

f(2a - x) = [1 / √(2phi)] e^-(2a-x-3)²/2

= [1 / √(2phi)] e^-(x-3)²/2

= f(x)

Therefore, X and Y are symmetric about 3.

Answer: (c) X and Y are symmetric about 3.

To know more about probability density function, visit:

https://brainly.com/question/31039386

#SPJ11

The long-range prediction for the proportion of students in each group is approximately 14.2% in Group 1, 20.6% in Group 2, 34.5% in Group 3, and 30.7% in Group 4. The number of testing periods required for at least 70% of the students to have increasing values of n cannot be determined without specific values.

To find the long-range prediction for the proportion of students in each group, we need to calculate the steady-state vector of the transition matrix. The steady-state vector represents the long-term proportions of students in each group. We can find this vector by solving the equation:

π * P = π

where π is the steady-state vector and P is the transition matrix.

The given transition matrix is:

Copy code

0.325  0.05   0.021  0

0.415  0.311  0.351  0.194

0.144  0      0.327  0.485

0      0.188  0      0.812

Let's solve for the steady-state vector using matrix calculations. We can represent the steady-state vector as π = [π1, π2, π3, π4]. Therefore, the equation can be rewritten as:

[π1, π2, π3, π4] * P = [π1, π2, π3, π4]

This gives us the following system of equations:

π1 * 0.325 + π2 * 0.415 + π3 * 0.144 = π1

π1 * 0.05 + π2 * 0.311 + π3 * 0.188 + π4 * 0.188 = π2

π1 * 0.021 + π2 * 0.351 + π3 * 0.327 = π3

π2 * 0.194 + π3 * 0.485 + π4 * 0.812 = π4

We also know that the sum of the probabilities in the steady-state vector must be 1:

π1 + π2 + π3 + π4 = 1

Now we can solve this system of equations to find the steady-state vector.

Copy code

0.325π1 + 0.415π2 + 0.144π3 = π1

0.05π1 + 0.311π2 + 0.188π3 + 0.188π4 = π2

0.021π1 + 0.351π2 + 0.327π3 = π3

0.194π2 + 0.485π3 + 0.812π4 = π4

π1 + π2 + π3 + π4 = 1

Solving this system of equations, we find:

π1 ≈ 0.142

π2 ≈ 0.206

π3 ≈ 0.345

π4 ≈ 0.307

Therefore, the long-range prediction for the proportion of students in each group is approximately:

Group 1: 14.2%

Group 2: 20.6%

Group 3: 34.5%

Group 4: 30.7%

Now, let's move to part (b) of the question.

If all students are initially in Group 1, we need to determine the number of testing periods required for at least 70% of the students to have increasing values of n.

To calculate this, we can repeatedly multiply the initial state vector [1, 0, 0, 0] by the transition matrix until at least 70% of the students are in Group 4. We'll keep track of the number of testing periods until this condition is met.

less

Copy code

Initial state vector: [1, 0, 0, 0]

Transition matrix:

[0.325, 0.05, 0.021, 0]

[0.415, 0.311, 0.351, 0.194]

[0.144, 0, 0.327, 0.485]

[0, 0.188, 0, 0.812]

Starting with the initial state vector, we can calculate the new state vector as follows:

State vector after 1 period: [1, 0, 0, 0] * Transition matrix

State vector after 2 periods: [1, 0, 0, 0] * Transition matrix * Transition matrix

State vector after 3 periods: [1, 0, 0, 0] * Transition matrix * Transition matrix * Transition matrix

and so on...

We will continue this calculation until the proportion of students in Group 4 is at least 70%. The number of periods it takes to reach this point will be the answer.

Please note that the calculation involves matrix multiplication, which may require computational resources. If you need a specific number of testing periods, let me know and I can perform the calculation for you.

To learn more about transition matrix visit : https://brainly.com/question/31359792

#SPJ11

Answer:

34cm squared

Step-by-step explanation:

Formula: 2(WL+HL+HW)

(2*5) + (1*5) + (1*2) = 10 + 5 + 2  = 17 17*2 = 34

Answer:

34

Step-by-step explanation:

2(wl+ hl+hw)

2(10+5+2)

= 34

Answer:

x = 4, y = -6

Step-by-step explanation:

Elimination Method

3x + 4y = -12 ---- (1)

x-y = 10 ---- (2)

(2) x 4:

4(x) 4(-y) = 4(10)

4x - 4y = 40 ---- (3)

(1) + (3):

3x + 4y + (4x - 4y) = -12 + 40

3x + 4y + 4x - 4y = 28

7x = 28

x = 28/7

x = 4

Sub x = 4 into (2):

(4) - y = 10

-y = 10 - 4

-y = 6

y = -6

Answer:

-----------------------

The number of ways to choose the first place finisher is 25, since any of the 25 people can win.

After the first place finisher is determined, there are 24 people left who can finish in second place.

Therefore, the total number of ways is:

Correct choice is C.

Answer:

The first one.

Step-by-step explanation:

so 1 stands for x and -5 stands for y. When you plug in 1 into the equation the answer is -5. So that order pair works with that equation.