Stats parameter?

Question

The avg time in years to get an undergrad degree in stats was compared for men and women.Random samples of 100 men and 100 women with a major in stats were taken.Select the appropriate parameter:

1) one population proportion p

2) the difference between 2 pop. parameters p1-p2

3) one population mean u1

4) the difference between 2 population means u1-u2

5) ud the mean difference between u1 and u2

Answer 1

The answer you are looking for is

4) the difference between 2 population means u1-u2

Hypothesis Test for the difference in means:

Let X be a large sample of size n, let Y be a large sample of size m were X and Y come from populations with means μx and μy and standard deviations σx and σy and X and Y are independent then:

to test the null hypothesis

H0: μx - μy = Δ or

H0: μx - μy ≤ Δ or

H0: μx - μy ≥ Δ

find the test statistic z = ((xBar - yBar) - Δ) / (sqrt(σx² / n + σy² / m)

where xbar is the sample average of sample X

ybar is the sample average of sample Y

sx is the sample standard deviation of X, which is used if σx is unknown

sy is the sample standard deviation of Y, which is used if σy is unknown

The p-value of the test is the area under the normal curve that is in agreement with the alternate hypothesis.

H1: μx - μy ≠ Δ; p-value is the area in the tails greater than |z|

H1: μx - μy > Δ; p-value is the area in the tails to the right of z

H1: μx - μy < Δ; p-value is the area in the tails left of z.