# The Difference between Two Means

## Questions

Question 1 out of 9.
The graphs show a violation of the assumption of (check all that apply)

• normality
• homogeneity of variance

Question 2 out of 9.
The graphs show a violation of the assumption of (check all that apply)

• normality
• homogeneity of variance

Question 3 out of 9.

The graphs show a violation of the assumption of (check all that apply)

• normality
• homogeneity of variance

Question 4 out of 9.

In the formula for $t$, the "statistic" is

• the null hypothesis.
• the mean of all numbers.
• the difference between sample means.
• the significance level.

Question 5 out of 9.

In the formula for $t$, the "hypothesized value" is

• what you expect the $t$ to be.
• the difference between population means.
• the significance level.

Question 6 out of 9.

If the null hypothesis is that two population means are equal, then the hypothesized value is

• 0.
• the population mean.

Question 7 out of 9.

The denominator in the $t$ test formula is

• the estimated standard error of the mean.
• the estimated standard error of the difference between means.
• MSE/2

Question 8 out of 9.
If there are 4 scores per group and the $t$ value is 2.34, what is the $p$ value for a two-tailed test (to 3 decimal places)?

___________

Question 9 out of 9.
What is the t for an independent-groups $t$ test for these data?

___________

  G 1	  G 2
46	 28
59	 37
53	 40
35	 34
43	 29
28	 46
59	 26
51	 41