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1 year ago

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Two independent simple random samples are taken to test the difference between the means of two populations whose variances are

not known, but are assumed to be equal. The sample sizes are n1 = 32 and n2 = 40. The correct distribution to use is the
a. t distribution with 73 degrees of freedom
b. t distribution with 72 degrees of freedom
c. t distribution with 71 degrees of freedom
d. t distribution with 70 degrees of freedom

1 answer:

My name is Ann [436]1 year ago

3 0

I think it’s 72 degrees of freedom

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Define a function f on a set of real numbers as follows: f(x) = 3x − 1 x , for each real number x ≠ 0 Prove that f is one-to-one

dalvyx [7]

Answer with Step-by-step explanation:

We are given that

$f(x)=\frac{3x-1}{x}$

For each real number $x\neq 0$

To prove that f is one -to-one.

Proof:Let $x_1$ and $x_2$ be any nonzero real numbers such that

$f(x_1)=f(x_2)$

By using the definition of f to rewrite the left hand side of this equation

$f(x_1)=\frac{3x_1-1}{x_1}$

Then, by using the definition of f to rewrite the right hand side of this equation of $f(x_1)=f(x_2)$

$f(x_2)=\frac{3x_2-1}{x_2}$

Equating the expression then we get

$\frac{3x_1-1}{x_1}=\frac{3x_2-1}{x_2}$

$3x_1x_2-x_2=3x_2x_1-x_1$

$3x_1x_2-3x_1x_2+x_1=x_2$

$x_1=x_2$

Therefore, f is one-to-one.

6 0

1 year ago

The ratio of the number of miles Kyle drives to the number of hours he is driving is 468 to 9. What is Kyle's rate of speed? A)

mr_godi [17]

Answer:

the answer is 52

Step-by-step explanation:

you have to divide 468 by 9 and should get you too 52

3 0

2 years ago

Read 2 more answers

during the summer winnie delivers flowers and bob babysits for neighbors to show their earnings winnie makes a table which state

miv72 [106K]

Winnie earns $12.30 and Bob earns $24.30.
Bob earns $8.10 and earns$4.10
Winnie earns$12.15 and Bob earns $6.15
Winnie earns $4.05 and Bob earns $2.05

7 0

1 year ago

Read 2 more answers

Consider this claim: Changes in environmental conditions always result in new ecosystems and loss of biodiversity characterized

Dafna11 [192]

Answer:

If a desert became flooded, some species would immeadiately go extinct, distrupting the ecosystem, biodiversity, and the food web. This flood might cause new species to enter the ecosystem as well, through means such as rafting. Other species would be forced to adapt to the new environment, leading to adaptation and possibly speciation. For a time the ecosystem would not be very stable, but after a relatively short time, 10 or 20 years, the ecosystem could stabilize itself. So my conclusion is that ecosystems are relatively fluid, they can adapt to almost anything if they have enough time and the change in environment isn’t too drastic.

Step-by-step explanation:

4 0

1 year ago

6 questions = 30 points someone please help me

eduard

Answer:

1)D

2)D

3)A

4)B

5)Cannot Answer - No data

6)C

7)C

6 Questions answered for 30 points.

Step-by-step explanation:

Answer for the 1st Question,

Area of a cylinder can be calculated by,

Area of the cylindrical part = $2\pi rL$

Area of the parts that cover the open parts of cylinder = $2\pi r^2$

Therefor Total are of the cylinder = $2\pi rL+2\pi r^2$

Area of the total cylinder = $2*3.14*6.8*14.2+2*3.14*6.8^2$

= $896.784$

<u>Therefor best estimate will be D) 923 in^2</u>

Answer for the 2nd Question,

ABC is a triangle.

By Pythagorean theorem it says,

$(AC)^2+(CB)^2=(AB)^2$

The distance from A to C = 6

The distance from C to B = 5

$(AC)^2=6^2=36$

$(CB)^2=5^2=25$

$(AC)^2+(CB)^2=(AB)^2=36+25=61$

Therefor $(AB)^2=61\\(AB)=\sqrt{61}$

<u>Therefor Answer is D) Sqr 61</u>

Answer to Question 3

To find the trend you can draw an imaginary line that fits the scatter plots.(I have attached a image drawing the imaginary lines)

Then the revenue can be calculated by calculating the area covered by the imaginary line drawn or area "under" the curve.

Area of the Store 1 = $\frac{1}{2} *(110+40)*110=8250$

Area of the Store 2= $\frac{1}{2} *110*80=4400$

Therefore Revenue from Store 1 = $8250

Revenue from Store 2 = $4400

<u>Answer is A) Store 1 has more sales revenue</u>

Answer for Question 4

$\frac{5}{12}=0.4167\\\frac{5}{11}=0.4545$

You can straight away discard answer D because it is less than both 5/12 and 5/11.

Also you can discard Answer C because 25/264 is very small (less than 1/10=0.1)

$\frac{11}{23} =0.4782$ , therefor this is not in between those two numbers.

Then it has to be $\frac{115}{264} =0.4356$

<u>Answer is B)</u>

Answer for question 6

The equation of a straight line is of the form $y=mx+c$

here m is the gradient and c is the intercept.

Find the intercept(c) by finding the y value when x value is 0, here it is +1.

Gradient (m) of the graph can be found by,

$\frac{y1-y2}{x1-x2} =\frac{7-3}{3-1} =2$

Therefor the equation of the graph is,

$y=2x+1$

<u>Answer is C</u>

Answer for question 7

$\frac{7}{8} =0.875$

$\frac{6}{9} =0.67$

We can discard answer A because the value is close to 0.5

We can discard answer B because 3/17 is a very small value (0.17)

$\frac{53}{72} =0.73$ , This falls between the above 2 numbers.

<u>Therefor answer is C</u>

5 0

2 years ago