Conservationists have despaired over destruction of tropical rain forest by logging, clearing, and burning." These words begin a report on a statistical study of the effects of logging in Borneo. Here are data on the number of tree species in 12 unlogged forest plots and 9 similar plots logged 8 years earlier:

Col1 Unlogged 2218 222015121 13 13 1913 19 15

Col2 Logged 17 4 181418151510 12 Use the data to give a 90% confidence interval for the difference in mean number of species between unlogged and logged plots. Compute degrees of freedom using the conservative methoo. Interval: ________to__________.

Answers

Answer 1

Answer: -8.16 to 15.84

Step-by-step explanation: Confidence Interval is an interval in which we are a percentage sure the true mean is in the interval.

A confidence interval for a difference between two means and since sample 1 and sample 2 are under 30, will be

[tex]x_{1}-x_{2}[/tex] ± [tex]t.S_{p}\sqrt{\frac{1}{n_{1}}+\frac{1}{n_{2}} }[/tex]

where

x₁ and x₂ are sample means

t is t-score

[tex]S_{p}[/tex] is estimate of standard deviation

n₁ and n₂ are the sample numbers

The estimate of standard deviation is calculated as

[tex]S_{p}=\sqrt{\frac{(n_{1}-1)s_{1}^{2}+(n_{2}-1)s_{2}^{2}}{n_{1}+n_{2}-2} }[/tex]

where

s₁ and s₂ are sample standard deviation of each sample

Degrees of freedom is:

[tex]df=n_{1}+n_{2}-2[/tex]

df = 12 + 9 - 2

df = 19

Checking t-table, with 90% Confidence Interval and df = 19, t = 1.729.

The mean and standard deviation for 12 unlogged forest plots are 17.5 and 3.53, respectively.

The mean and standard deviation for 9 logged plots are 13.66 and 4.5, respectively.

Calculating estimate of standard deviaton:

[tex]S_{p}=\sqrt{\frac{(12-1)(3.53)^{2}+(9-1)(4.5)^{2}}{12+9-2} }[/tex]

[tex]S_{p}=\sqrt{\frac{299.07}{19} }[/tex]

[tex]S_{p}=[/tex] 15.74

The difference between means is

[tex]x_{1}-x_{2}[/tex] = 17.5 - 13.66 = 3.84

Calculating the interval:

[tex]t.S_{p}\sqrt{\frac{1}{n_{1}}+\frac{1}{n_{2}} }[/tex] = [tex]1.729.15.74.\sqrt{\frac{1}{12} +\frac{1}{9} }[/tex]

[tex]t.S_{p}\sqrt{\frac{1}{n_{1}}+\frac{1}{n_{2}} }[/tex] = [tex]27.21\sqrt{\frac{21}{108} }[/tex]

[tex]t.S_{p}\sqrt{\frac{1}{n_{1}}+\frac{1}{n_{2}} }[/tex] = [tex]27.21\sqrt{0.194}[/tex]

[tex]t.S_{p}\sqrt{\frac{1}{n_{1}}+\frac{1}{n_{2}} }[/tex] = 12

Then, interval for the difference in mean is 3.84 ± 12, which means the interval is between:

lower limit: 3.84 - 12 = -8.16

upper limit: 3.84 + 12 = 15.84

The interval is from -8.16 to 15.84.


Related Questions

Type your solution as an ordered pair.

Answers

Answer and Step-by-step explanation:

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Hi there! This is what the graph should look like: (Look at the picture attached)

We can see that the solution to the equation is (3, -2) because this is where the lines intersect.

*^*^*^*^*^*^*^*^*^*^*^*^*^*^*^*^*^*^*^*^*^*^*^*^*^*^*^*^*^*^*^*^*^*^*^*^*^*^*^*^*^*^

#teamtrees #WAP (Water And Plant)

need help asap with these

Answers

Answer:

1. 6n - 15

2. x + 10

3. -4d + 15

4. true, associative property

5. distributive, commutative

Step-by-step explanation:

1. distribute 3/4 into the parentheses, so multiply 3/4 * 8 and 3/4 * -20

2. distribute the 2 into the parentheses so multiply 2 * 3x and 2 * 5, then combine like terms

3. distribute -3 into the parentheses so -3 * 4D and -3 * -5 then add like terms

4. add like terms on both sides of the equal sign and you get 10x on both sides. this is the associative property because it doesn't matter what's inside or outside the parentheses you get the same answer no matter how you add them up

5. the first part is distributive because you distributed the three into the parentheses and the second part is commutative because you switch them around and you can get the same answer

Una recta que pasa por los puntos A (2,1) y B (6,3) y otra recta pasa por A y por el punto (0,y) ¿Cuánto vale y, si ambas rectas son perpendiculares?

Answers

The translation of the question given is

A line that passes through the points A (2,1) and B (6,3) and another line passes through A and through the point (0, y). What is y worth, if both lines are perpendicular?

Answer:

y = 5

Step-by-step explanation:

Line 1 that passes through A (2,1) and B (6,3)  

Slope (m1) = 3-1/6-2 = 2/4 = 1/2

y - 1 = [tex]\frac{1}{2}[/tex] ( x -2)

2y - 2 = x- 2

y = [tex]\frac{x}{2}[/tex]

Line 2 passes through A (2,1) and (0,y)

slope (m2) =[tex]\frac{y-1}{-2}[/tex]

Line 1 and Line 2  are perpendicular

m1*m2 = -1

[tex]\frac{1}{2}[/tex]  * [tex]\frac{y-1}{-2}[/tex] = -1

y-1 = 4

y = 5

slope = -2

Equation of Line 2

Y-1 = -2(x-2)

y -1 = -2x +4

2x +y = 5

The image below shows the download speed of three different companies. Use the information to answer the questions.

Complete questions 1-5 in order.

1) What is the download speed in MB per minute for AT&T?

2) What is the download speed in MB per minute for Bidmore?

3) What is the download speed in MB per minute for Comcast?

4) Who has the best download speed? Explain your choice.

5) All these equations show proportional relationships. Bid more's graph is shown, what would the other two graphs look like for AT&T and Comcast?
They will go through _________and be a __________line.

Answers

Answer:

1) The download speed for AT&T is 1,800

2) The download speed for Bidmore is 1,500

3) The download speed for Comcast is 1,680

4) AT&T has the best download speed out of the three.

5) They will go through the origin and be a proportional line.

Step-by-step explanation:

What is -3 4/9 • 5 2/5

Answers

The answer is -18 3/5

See attachment for answer.

The answer is -93/5.

Please help me with this please

Answers

Answer: The second to last option I think

Step-by-step explanation:

Answer:i think its the The second

Step-by-step explanation:   so  look 2x6=12 and 4x2=8 so the snswers are on the right and the question is on the left holpfuly that helps

Make x the subject of h = 4(x + 3y )+ 2

Answers

Answer:

x =h-12y-2/4

Step-by-step explanation:

h = 4x +12y +2

h-12y-2=4x

thus x = h - 12y - 2 / 4

through (4,-3) parallel to y=-2x

Answers

Answer:

y = -2x + 5

Step-by-step explanation:

Parallel lines have the same slope, so the line's slope would be -2.

Because we have a coordinate point and the slope of the line, we can figure out the equation by using the point slope formula:

( y - y1 ) = m( x - x1 )

( y - ( - 3 ) ) = -2 ( x - 4 )

y + 3 = -2x + 8

y = -2x + 5

The equation of the line is y = -2x + 5

1. Write an equivalent
expression for
3x + 12 +7x + x

Answers

Answer:

11x+12

Step-by-step explanation:

combine like terms

Answer : 11x + 12

(:

6. Write the equation of the line in slope-intercept form given the following:
Point (-4,-4) and Slope of
5/4

Answers

Answer:

[tex]y=\dfrac{5}{4}x+1[/tex]

Step-by-step explanation:

Slope intercept form a equation of a line is given by the following formula:

Slope intercept form:

[tex]y=mx+c[/tex]

Given that, a point is (-4,-4)

i.e.

[tex]x=-4,\\y=-4[/tex]

Slope, [tex]m =\frac{5}{4}[/tex]

Putting the given values in the Slope intercept form equation:

[tex]-4=-4\times \dfrac{5}{4}+c\\\Rightarrow -4=-5+c\\\Rightarrow c =1[/tex]

Putting the value of [tex]c[/tex] and [tex]m[/tex] in the slope intercept form:

[tex]y=\dfrac{5}{4}x+1[/tex]

Nico y Manuel llevaron sus taps a la escuela para jugar a la hora de recreo. Nico coloco sus 7 taps en el piso y guardo los demás en una bolsa ¿cuantos taps podría tener Manuel en la bolsa

Answers

Answer:

7 o más

Step-by-step explanation:

lógicamente, si el juego necesitaba 7 taps para jugar y Nico tiene más de 7 taps, entonces Miguel también debería tener 7 o más taps en su bolsa.

WHOEVER ANSWERS FIRST GETS BRAINLEST!

The number p of pennies in Jorge's bank is one fourth the number of nichels, The wokal
number of coins in the bank is 25,
Which equation could be used to find m?
n= 25
06 A-' = 25
+ 2n = 25

Answers

Answer:

C

Step-by-step explanation:

what is what3 2/3 - 3/5 as a fraction plz give awnser

Answers

Answer:

55/15-9/15=46/15 or 3 1/15

Step-by-step explanation:

Answer:

46/15  or  3 1/5

Step-by-step explanation:

Hope this helps and have a Great Day :)

A printer can print 12 color pages in 3 minutes.
How many color pages can the printer print in 9
minutes?

Answers

Answer:

36

Step-by-step explanation:

12/3 = 4 pages per minute

4*9 = 36

Answer:

36

Step-by-step explanation:

12*3=36

A pilot takes a taxi from the airport and the hotel. The taxi driver charges a $2.50 fee plus $2.65 per mile. Write an equation that can be used to find y, the total cost of the trip, if x represents the number of miles on the trip.

Answers

Answer:

2.50 + 2.65x = y

Step-by-step explanation:

The 2.50 fee won't change but the price per mile will, each mile will cost $2.65 more. And since we don't know how many miles the plot is taking, $2.65x. Then the total cost is y

Answer:

Step-by-step explanation: if the 2.50 is staying the same, then the answer is y=2.50x + 2.65

The ratio of boys to girls in a class is 2:3. There are 30 students in the class. How many more girls than boys are there?

Answers

Answer:

there are 18 girls

Step-by-step explanation:

for every 2 boys there are 3 girls

so then you can say 2/5 of the class are boys and 3/5 are girls

and you have to calculate 3/5 of 30 so you have to divide 5 and then multiply by 3 so 30 divided by 5 is 6 the n multiply 6 by 3 and the answer is 18.

Hope this helps

(Select all that are correct) which statements describe key features of function g if g(x) = f(x + 2)

a. y-intercept at (0,4)
b. domain of {x|-♾️< x <♾️}
c. horizontal asymptote of y = 0
d. horizontal asymptote of y=2
e. y-intercept at (0,1)​

Answers

Answer:

Y-intercept (0,1) / Domain (-infinite,infinite) / horizontal asymptote y=0

The y-intercept is: (0,1)

The domain is [tex]\{x|-\infty < x < \infty\}[/tex]

The horizontal asymptote is [tex]y = 0[/tex]

The given parameters from the complete question are:

[tex]f(x) = 2^{x-2}[/tex]

[tex]g(x) = f(x + 2)[/tex]

First, we calculate the function of g(x)

[tex]g(x) = f(x + 2)[/tex]

Calculate f(x + 2)

[tex]f(x) = 2^{x-2}[/tex]

[tex]f(x + 2) = 2^{x+2-2}[/tex]

[tex]f(x + 2) = 2^x[/tex]

So:

[tex]g(x) = 2^x[/tex]

Start by calculating the y intercept:

This means, we calculate the g(x) when [tex]x=0[/tex]

[tex]g(x) = 2^x[/tex]

[tex]g(0) = 2^0[/tex]

[tex]g(0) =1[/tex]

The above computation means (a) is incorrect; but (e) is correct.

Next, calculate the domain of g(x)

[tex]g(x) = 2^x[/tex]

Some features in a function that limit the x values are: roots, fractions, etc.

[tex]g(x) = 2^x[/tex] does not have any restricting value of x.

This means the value of x ranges from negative infinity to positive infinity.

Hence, the domain is: [tex](-\infty,\infty)[/tex]

The above computation means (b) is correct

Next, calculate the horizontal asymptote.

To do this, we plot the graph of g(x) --> see attachment

Then we trace a horizontal line from the horizontal part of the curve of g(x) till it gets to the y-axis.

From the attached graph of g(x), the line touches the y-axis at [tex]y = 0[/tex]

So, the horizontal asymptote is: [tex]y = 0[/tex]

Read more at:

https://brainly.com/question/8120140

What is the product?

(6) (negative 12)
–82
–72
72
82

Answers

Answer:

-72 is the answer.........

6 times -12 so it’s -72

At which plant is the cost lowest for producing 5 radios?

Answers

Answer:

plant c is the answer to your question

state the common difference for the given A.P.3/2,1/2,-1/2,-3/2,......​

Answers

Answer:

-1

Step-by-step explanation:

The common difference is the constant amount of change between the numbers in an arithmetic sequence.

To find the common difference, you take the last term and subtract it by the previous term.

[tex]\frac{-3}{2} - \frac{-1}{2} =-1[/tex]

Gcf of 80x^3 and 30yx^2

Answers

The answer is 30xy3 2 +1
Answer:
10x^2
That's what I got

Rewrite, using the distributive property. -3(20 + -29d) = [?] + [ ]d​

Answers

Answer:

-60+87d

     or

87d-60

Step-by-step explanation:

-3(20+-29d)=

-60+87d

how do I evaluate cos 4π/3?

Answers

Answer:

-1/2

Step-by-step explanation:

cos (4π/3)= cos (π+π/3)

Answer:

Step-by-step explanation:

[tex]cos (\frac{4 \pi }{3} )=cos (\pi +\frac{\pi }{3} )=-cos (\frac{\pi }{3} )=-\frac{1}{2}[/tex]

A dolphin jumps 54 times in a 6 hour period. At this rate, how many jumps would be expected in a 2 hour period?

Answers

answer is 18
u gotta find out how many jumps per hour first so do 54/6= 9
then multiply by 2
9 x 2 = 18

f(x)=3x+12 and g(x)=4x-8 find h(x)=f(x)+g

Answers

Sorry yyyyyyyyyyyyyyyyyyyyy

Lea solves the equation below by first squaring both sides of the equation.
3+2y=√-y
What extraneous solution does Lea obtain?
y=

Answers

Answer: IF YOU ARE ON KHAN ACADEMY THE ANSWER IS NOT -1

THE CORRECT ANSWER ON KHAN IS -9/4

For equation 3 + 2y = √(-y) the extraneous solution does Lea obtain is y = (-13 + √97) / 8 or y = (-13 - √97) / 8

What is quadratic equation?

A quadratic equation is a second-order polynomial equation in a single variable x , ax²+bx+c=0. with a ≠ 0 .

When Lea squares both sides of the equation 3 + 2y = √(-y), she gets:

(3 + 2y)² = (-y)

Expanding the left side, we get:

9 + 12y + 4y² = -y

Bringing all the terms to one side, we get a quadratic equation:

4y² + 13y + 9 = 0

We can solve this quadratic equation using the quadratic formula:

y = (-b ± √(b² - 4ac)) / 2a

Substituting the coefficients a = 4, b = 13, and c = 9, we get:

y = (-13 ± √(13² - 4(4)(9))) / 2(4)

y = (-13 ± √97) / 8

So the solutions are:

y = (-13 + √97) / 8 or y = (-13 - √97) / 8

Hence, the extraneous solution does Lea obtain is y = (-13 + √97) / 8 or y = (-13 - √97) / 8

To learn more on Quadratic equation click:

https://brainly.com/question/17177510

#SPJ2

Plz help me answer this question

Answers

Answer: 4/5 - 2

Step-by-step explanation:

Simply put it into a graphing calculator

Find the volume of the cylinder. Use 3.14 as π.

Answers

Where is the question?

Is this relationship proportional?

Carrots (lb)
2 | 3 | 4
Number of carrots
23 | 33 | 43

Answers

yes it is because of the way that it is set up

Answer:

4

Step-by-step explanation:

The value of x + x(xx) when x = 2 is:

Answers

Answer:

10

Step-by-step explanation:

X+x(xx)

X+x(x^2)

X+x^3

2+2^3

10

Answer:

10.

Step-by-step explanation:

2 + 2 x (2x2)

= 2 + 2 x 4

= 2 + 8

= 10

Hope that helped, :)

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