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3 years ago

What is the correlation coefficient ?

Mathematics

1 answer:

steposvetlana [31]3 years ago

3 0

Answer:

r = correlation coefficient

Step-by-step explanation:

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A student researcher compares the heights of men and women from the student body of a certain college in order to estimate the d

maria [59]

Answer:

(0.6613, 8.3387)

Step-by-step explanation:

Let the heights of men be the first population and the heights of women be the second population. Then

We have $n_{1} = 15$ , $\bar{x}_{1} = 69.4$ , $s_{1} = 3.09$ and

$n_{2} = 7$ , $\bar{x}_{2} = 64.9$ , $s_{2} = 2.58$ . The pooled

estimate is given by

$s_{p}^{2} = \frac{(n_{1}-1)s_{1}^{2}+(n_{2}-1)s_{2}^{2}}{n_{1}+n_{2}-2} = \frac{(15-1)(3.09)^{2}+(7-1)(2.58)^{2}}{15+7-2} = 8.68$

The 99% confidence interval for the true mean difference between the mean height of the men and the mean height of the women is given by (if the samples are independent)

$(\bar{x}_{1}-\bar{x}_{2})\pm t_{0.01/2}s_{p}\sqrt{\frac{1}{15}+\frac{1}{7}}$ , i.e.,

$(69.4-64.9)\pm t_{0.005}2.946\sqrt{\frac{1}{15}+\frac{1}{7}}$

where $t_{0.005}$ is the 0.5th quantile of the t distribution with (15+7-2) = 20 degrees of freedom. So

$4.5\pm(-2.845)(2.946)(0.458)$ , i.e.,

(0.6613, 8.3387)

5 0

3 years ago

Expand and simplify <br> 4(2x+3)+ 4(3x+2)

stepladder [879]

Answer:

20x + 20

Step-by-step explanation:

4(2x+3)+ 4(3x+2)

Expand the brackets.

8x + 12 + 12x + 8

Now simplify.

20x + 20

6 0

3 years ago

Can someone help.....

tatyana61 [14]

Answer:

Step-by-step explanation:

formula for circumference of a circle is $\pi$ d

7 $\pi$ = $\pi$ d

d = 7

5 0

3 years ago

Victor is ordering pizzas for a party. He would like to have 1/4 of a pizza for each guest. He can only order whole pizzas, not

scoundrel [369]

Since everyone is getting a quarter of a pizza, 27 divided by 4 is 6.75. 6.75 rounded to a whole number is 7.

3 0

3 years ago

Four runners are training for long races. Noah Ran 5.123 miles. Andre ran 6.34 miles. Jada ran 7.1 miles. Diego ran 8 miles.

Korolek [52]

Jada ran 1.977 miles more than Noah

3 0

3 years ago