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3 years ago

Please help please

Mathematics

1 answer:

mihalych1998 [28]3 years ago

8 0

I think its D I’m sorry if I’m incorrect

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10.

Kay [80]

Answer:

$\frac{(82)(2.4)^2}{104.139} \leq \sigma^2 \leq \frac{(82)(2.4)^2}{62.132}$

$4.535 \leq \sigma^2 \leq 7.602$

Now we just take square root on both sides of the interval and we got:

$2.2 \leq \sigma \leq 2.8$

And the best option would be:

A. 2.2 < σ < 2.8

Step-by-step explanation:

Information provided

$\bar X=32.1$ represent the sample mean

$\mu$ population mean

s=2.4 represent the sample standard deviation

n=83 represent the sample size

Confidence interval

The confidence interval for the population variance is given by the following formula:

$\frac{(n-1)s^2}{\chi^2_{\alpha/2}} \leq \sigma^2 \leq \frac{(n-1)s^2}{\chi^2_{1-\alpha/2}}$

The degrees of freedom are given by:

$df=n-1=83-1=82$

The Confidence is given by 0.90 or 90%, the value of $\alpha=0.1$ and $\alpha/2 =0.05$ , the critical values for this case are:

$\chi^2_{\alpha/2}=62.132$

$\chi^2_{1- \alpha/2}=104.139$

And replacing into the formula for the interval we got:

$\frac{(82)(2.4)^2}{104.139} \leq \sigma^2 \leq \frac{(82)(2.4)^2}{62.132}$

$4.535 \leq \sigma^2 \leq 7.602$

Now we just take square root on both sides of the interval and we got:

$2.2 \leq \sigma \leq 2.8$

And the best option would be:

A. 2.2 < σ < 2.8

3 0

3 years ago

She estimates 3/4 cups of snack mix , how many snack mix she needs in order to make 200 servings

Elenna [48]

<span>She estimates 3/4 cups of snack mix for each serving.
how many snack mix she needs in order to make 200 servings ?
We have 3/4 x 200= 3*50= 150 cups of snacks
Have fun
</span>

5 0

4 years ago

Find the area under the standard normal distribution curve between z = 0 and z = 2.16.

Vladimir79 [104]

do you have a z table chart to look at?

find Z= 0 should show that z=0 = 0.500

and z=2.16 = 0.9846

subtract them

0.9846-0.500 = 0.4846 is the area

7 0

3 years ago

(x^2)(x^7)(x^-3) eliminate negative exponent

Delicious77 [7]

Answer:

x^6

Step-by-step explanation:

5 0

3 years ago

Read 2 more answers

use the Pythagorean theorem to find the measure of the hypotenuse of right triangle of the measures of the legs are 30 meters an

DochEvi [55]

A² + b² = c²
30² + 72² = c²
<u />900 + 5,184 = c²
6084 = c²
(Square root both sides)
c = 78 m
<u />

6 0

3 years ago