Question

You are given two independent random samples from two populations.

For Sample #1, there are 60 observations, the sample mean is 33.8 and you are given that the populationstandard deviation is 5.5

For Sample #2, there are 35 observations, the sample mean is 31.8 and you are given that the populationstandard deviation is 4.1

You are asked to test the null hypothesis that the two population have the same mean (the difference in population means is 0).

What is the value of the test statistic for this hypothesis?

Question 4 options:

	2.565
	1.922
	2.244
	2.090
	2.016
	2.344
	1.645
	1.892
	1.960
	2.122
	1.877

Given this date, which of the following statements is correct

Question 5 options:

	We cannot reject the null hypothesis at the 10% level
	We can reject the null hypothesis at the 10% level, but not at the 5% level
	We can reject the null hypothesis at the 5% level, but not at the 1% level
	We can reject the null hypothesis at the 1% level
	We cannot reject the null hypothesis at any level

Answer 1

1)

x1            =	33.80	x2            =	31.80
n1           =	60	n2           =	35
σ1           =	5.50	σ2           =	4.10
std error σx1-x2=√(σ21/n1+σ22/n2)    =			0.992
test stat z =(x1-x2-Δo)/σx1-x2     =			2.016

p value : =

0.044

We can reject the null hypothesis at the 5% level, but not at the 1% level