Let X be the percentage score on a college-entrance exam for students who did not participate in an exam-preparation seminar. X is modeled by a uniform distribution on [a,100]. Let Y be the percentage score on a college-entrance exam for students who did participate in an exam-preparation seminar. Y is modeled by a uniform distribution on [1.25a,100]. It is given that E[X^2] = 19,600/3.Calculate the 80th percentile of Y. A. 80 B. 85 С. 90 D. 92 E. 95
Answer:
E. 95
Step-by-step explanation:
[tex]\text{Given that:} \\ \\ X \sim U(a,100) \\ \\ fx(x) = \dfrac{1}{100-a} \\ \\ E[X^2] = \int _x f_x (x) \ dx \\ \\ \implies \int^{100}_{a} \dfrac{x^2}{100-a}dx \\ \\ =\dfrac{100^3-a^3}{3(100-a)} \\ \\ =\dfrac{100^2+100a+a^2}{3} \\ \\ E[X^2] = \dfrac{19600}{3}=\dfrac{100^2+100a+a^2}{3} \\ \\\implies a^2 +100a+10000=19600 \\ \\ \implies a^2 +100a -9600 = 0 \\ \\ \implies a = \dfrac{-100 \pm \sqrt{100^2 -4(-9600)} }{2} \\ \\=\dfrac{-100 \pm \sqrt{48400}} {2} \\ \\ = \dfrac{-100 \pm 220}{2} \\= 60 \ OR \ 160[/tex]
[tex]\text{SInce X is a percentage score on an exam }\ P(X \ge 0) = 1 \text{which means } \ a = 60\\ \\Y \sim U (1.25a,100) = U(75,100)\\ \\ f_y(y) = \dfrac{1}{100-75} = \dfrac{1}{25} \\ \\ \text{Let assume the 80th percentile of Y be} \ y_{80} } \\ \\ \\Then; \ P(Y \le y_{80}) =80\% \implies \int^{y_{80}}_{75} \ f_Y (y) \ dy = 0.8 \\ \\ \implies \int^{y_{80}}_{75}\dfrac{1}{25} \ dy = 0.8 \\ \\ \implies \dfrac{y_{80}-75}{25}= 0.8 \\ \\ \implies y_{80} = 95[/tex]
A catering company charges a flat fee of 120$ to cater an event...
I'm begging for help. This is the third time i've posted this, and I'm so confused. I don't understand how to use this chart to get the fractional inches. I really need help, please help. :(
Answer:
yes, I am pretty sure you do .122 as 1/8 and you keep doing that. I am pretty sure :)
Step-by-step explanation:
Also could you please give me brainliest?
Answer:
was popping. Free points right
Step-by-step explanation:
A triangle has side lengths of 11 cm and 6 cm. Which could be the value of the third side, 21 cm or 14 cm? Is it 14 or 21?
Answer:
14
Step-by-step explanation:
As long as two sides of a triangle added together are larger than the third side, it is an accurate triangle!
Find the probability of being dealt a "jacks over aces" full house (three jacks and two aces). (Round your answer to six decimal places.)
Answer:
1.500000
Step-by-step explanation:
jacks over aces
3÷2
=1.5
correct to six decimal places
1.500000
Nicole took a taxi from her house to the airport. The taxi company charged a pick-up
fee of $2.90 plus $1.75 per mile. The total fare was $44.90, not including the tip.
Write and solve an equation which can be used to determine z, the number of miles
in the taxi ride
The first thing we need to do is to find the linear equation that defines the total cost of the taxi ride as a function of the number of miles traveled.
We will find that z = 24.
We know that the taxi charges a fixed fee of $2.90, plus $1.75 per mile.
So if you travel for z miles, the total cost will be:
[tex]c(z) = \$2.90 + \$1.75 \cdot z[/tex]
Now that we have this linear equation if we know that the total fare was $44.90, then we have:
[tex]c(z) = \$2.90 + \$1.75 \cdot z = \$44.90[/tex]
Now we just need to solve the above equation for z:
[tex]\$2.90 + \$1.75 \cdot z = \$44.90\\\\\$1.75 \cdot z = \$44.90 - \$2.90 = \$42.00\\\\z = \$42.00/\$1.75 = 24[/tex]
Then we can see that she traveled for 24 miles.
If you want to learn more, you can read:
https://brainly.com/question/19770987
Find the average rate of change of f(x)=x^2-4x+1 from x=3 to x=7 .
Answer:
7
Step-by-step explanation:
A number is multiplied by 3, then 5 is added to the product. The result is 17. Fin
the number. Round your answer to the nearest tenth.
Answer:4
Step-by-step explanation:
write a equation for each line
Answer:
Line l: y=4
Line m: y=-2x+4
Line n: y=x-1
Line p: x=-4
Hope this helps!
4. Jean and Mark are going to fill a pool with 2 different sized hoses. Jean can fill the pool in 4 hours, while Mark can complete it in 6 hours. Their supervisor thinks that the job will take 5 hours to
complete if they work together. Explain each step in solving this equation, and determine if the supervisor is correct or not.
Answer:
2.4 hours.
Step-by-step explanation:
Remark
The supervisor is not quite correct. The correct answer must be lower than the lowest number, otherwise you are taking out what the person with the narrower hose must be taking out what the other person is putting in.
Equation
Let x = the amount of time needed for him to fill the pool
Let y = the amount of time needed for the second person to fill the pool
Let z = the amount of time needed for both to fill the pool.
1/x + 1/ y = 1/z
1/4 + 1/6 = 1/z The common denominator is 12
3/12 + 2/12 = 1/z
5/12 = 1/z Cross multiply
5z = 12 * 1 Divide by 5
z = 12/5
z = 2 2/5
z = 2.4 hours
help me plz branniest to whoever is right
Answer:
x= -7, x=8
Step-by-step explanation:
factoring method..
f (x) = - x² + 12x - 20
= - x² + 10x + 2x - 20
= - x( x - 10 ) + 2( x - 10 )
= ( x - 10 ) ( -x + 2 )
=> x = 10, x = 2
Find two numbers whose sum is 9 and their difference is 60.
Smaller-
Large number-
Answer:
Step-by-step explanation:
x+y = 9
x-y = 60
-----------
2x = 69
x = 34.5
y = 9-x = -25.5
smaller number: -25.5
larger number: 34.5
I NEED HELP FAST! Which of the following sets of numbers could not represent the three sides of a triangle?
Answer:
Im pretty sure that 12, 18, and 29 would be the answer to your question.
Step-by-step explanation:
My sister plans to sell more than 250 boxes of cookies.
C>250
c250
Ob
Ос
Od
CS250
C2250
Next Page
Answer:
x > 250
Step-by-step explanation:
we are to express the statement using an inequality expression
Since my sister plans to sell more than 250 boxes of cookies, the inequality sign to use will be a greater than sign (>), since my sister is not selling amount less. Hence the required inequality will be x > 250 where;
x is the amount of box of cookies
Solve the equation square root of the quantity x plus 3 plus 4 equals 5 for the variable. Show each step of your solution process
Answer:
x=-2
Step-by-step explanation:
[tex]\sqrt{x+3}+4=5[/tex]
subtract 4 from each side
[tex]\sqrt{x+3} +4-4=5-4[/tex]
square both sides
[tex]\sqrt{x+3}^2=1^2[/tex]
so we have
[tex]x+3=1[/tex]
subtract 3 from each side
[tex]x+3-3=1-3[/tex]
so our answer is [tex]x=-2[/tex]
what is the area of this triangle?
Answer:
23,400
Step-by-step explanation:
30 times 30 times 26= 23,400
WILL MARK BRANILIEST PLZ HELP
Type the correct answer in the box. Use numerals instead of words, and round your answer to the nearest whole number.
Meghan flipped a quarter and rolled a standard six-sided die.
The probability that the coin landed on heads and the die landed on an even number is __%.
Answer:
25%
Step-by-step explanation:
Multiply the two probabilities.
P(heads)*P(even) = 1/2*1/2 = 1/4
1/4 = 25%
Which ordered pair is a solution of the equation?
-7x+3y=2
Choose 1 answer:
(Choice A)
A
Only (1,3)
(Choice B)
B
Only (−2,−4)
(Choice C)
C
Both (1,3)(-2,-4)
(Choice D)
D
Neither
Zorion’s mother helped him plan a budget. He had to put half of his money into savings. Whatever was left he split evenly into 3 categories: entertainment, snacks, and clothes. Which table correctly shows the budgeted amounts in each category if Zorion got $60 for selling his bike?
Answer:
it's the first one because it is split as the paragraph said it should
Please help me ?????!! Anyone help me ?!!!
Figure II is a translation image of Figure 1. Write a rule to describe
the translation.
Answer:
a translation of (-2,4)
Step-by-step explanation:
A ramp is elevated to a height of 27 inches from the base. The horizontal distance between the lower end of the ramp and the base is 69 inches, as shown in the figure. What is the length of the ramp?
Answer:
74.09453421...
Step-by-step explanation:
Pythagorean Theorem
You ride your bike to the park to meet your friend. The park is 75/100 of a mile away from your house. You ride your bike for 2/10 of a mile before you come to a steep hill. Then you walk your bike 1/10 to the top of the hill. When you get to the top of the hill, you can see the park up ahead. How far could you be away from the park when you are at the top of the hill?
Answer:
The answer is 0.45
Step-by-step explanation:
0.75-0.1-0.2=0.45
Please help soon!! I will give brainliest to the first correct answer!
Answer:
1(left) goes with 1
2(left) goes with 3
3(left) goes with 2
4(left) goes with 4
Step-by-step explanation:
2(5+6) = 22
3(5+3) = 24
2(4+5) = 18
2(3+2) = 10
10 + 12 = 22
8+ 10 = 18
15 + 9 = 24
6 + 4 = 10
1(left) goes with 1
2(left) goes with 3
3(left) goes with 2
4(left) goes with 4
Answer:
10 + 12 = 2(5+6) . 10+12=22, 5+6 = 11, 11×2 =22 or 2× (5+6) = 22.
8+10= 2(4+5) , 8+10=18. 2 × (4+5) = 18, 4+5=9, 9×2=18.
15+9= 3(5+3) , 15+9=24, 5+3=8, 8×3 =24 or 3× (5+3)
6+4= 2(3+2), 6+4=10, 3+2 = 5 , 5×2 =10
5th grade math. correct answer will be marked brainliest.
Answer:
Amy and Victor: 1 [tex]\frac{4}{9}[/tex]
Cal and Beth: [tex]\frac{7}{10}[/tex]
Beth and Victor [tex]\frac{5}{6}[/tex]
Step-by-step explanation:
Just multiply fractions by LCD
Consider the situations.
i. The value of an investment increases by $30 every year.
ii. The value of an investment decreases by 10% every year.
In which situation(s) is (are) the investment(s) changing at a constant rate?
both i and ii
only i
only ii
neither i norii
help someone plz I'll give brainlest
Answer:
like with the whole page?? cause if so i got this KINDA
Step-by-step explanation:
the first one (2/9+2/9) = 4/9
the second one (1/4+2/4)=3/4
the third one (3/8+5/8)=1 whole or 8/8
i cant see the last one so ill skip to the bottom row
the first one (2/5-1/5)=1/5
(9/12-4/12)=5/12
(4/10-2/10)= 2/10
and ill give someone else a shot with the rest of the questions but yw
this is pretty simple but hit me up if you ever need more help
=D
Answer:
Section 1
Adding and Subtracting- just add/subtract (depending on what the question is asking you) the numerators (top number), don't do anything to the denominators (bottom numbers)
Step-by-step explanation:
Section 1
Adding and Subtracting- just add/subtract (depending on what the question is asking you) the numerators (top number), don't do anything to the denominators (bottom numbers)
Section 2
Make the denominators (bottom numbers) the same, then add or subtract the numerators. To make the denominators same, apply a common factor to the bottom number.
Section 3
Multiply the top numbers and bottom numbers to get the answer.
Section 4
Use KCF: Keep, Change and Flip. Keep the first fraction the same, then change the division sign to a multiplication and finally flip the last fraction, then multiply the two fractions.
Solve 9≤c+1. Graph the solution.
The solution is
.
what is the measure of angle gxi?
Answer:
80
Step-by-step explanation:
80 because 8x10=80 and also 1x80=80
The measure of angle GXI from the given circle is equal to 60°.
What is the circle?A circle is a two-dimensional figure formed by a set of points that are at a constant or at a fixed distance (radius) from a fixed point (center) on the plane. The fixed point is called the origin or center of the circle and the fixed distance of the points from the origin is called the radius.
From the given figure, through the Centre 12 lines are passing and dividing the central angle.
We can write the measure of angle subtended by a single arc as -
θ = 360°/12
θ = 30°
So, the measure of ∠GXI = 2θ
= 2×30°
= 60°
So, ∠GXI = 60°
Therefore, the measure of ∠GXI is equal to 60°.
To learn more about the circle visit:
https://brainly.com/question/11833983.
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A+b=c what is c I need help
Answer:
has ft7shc63 queen, E5itee28 d74vyxb