A physical therapist wants to determine the difference in the proportion of men and women who participate in regular sustained physical activity. What sample size should be obtained if she wishes the estimate to be within three percentage points with 99​% ​confidence, assuming that ​(a) she uses the estimates of 22.6​% male and 18.1​% female from a previous​ year

A sample size of 1380 should be obtained.

Step-by-step explanation:

Minimum sample size:

The minimum sample size is of:

In which z is the critical value, related to the confidence level, E is the desired margin of error, and are the proportions.

99% confidence level

So , z is the value of Z that has a pvalue of , so .

Estimates of 22.6​% male and 18.1​% female from a previous​ year

This means that .

Within 3 percentage points, minimum sample size:

This is n for which . So

Rounding up:

A sample size of 1380 should be obtained.

i think it's ф or x=6,-6

step-by-step explanation:

-x^2=-36

x^2=-36

ф

or

if you mean by : -(x^2)=-36

it'll be: x^2=36

x=6,x=-6

hope it'll ! have a good day!

you for asking!

the correct option is 2.

step-by-step explanation:

according to the given information triangle abc is a right angle triangle with right angle at a. segment ab is 5 and segment ac is 7. point d is on segment bc and angles adb and adc are right angles.

it is given that triangles abd, cad, and cba are similar.

two triangles are similar if their corresponding sides are proportional.

in triangle cba, using pythagoras theorem

                      )

triangle abd and cba are similar,

                            (2)

triangle cad and cba are similar,

                      )

using (1), (2) and (3), we get

hence proved.

therefore option 2 is correct.