Week 1 - Statistical Theories and Application 2

If the null hypothesis states that there is no difference between the mean income of males and the mean income of females, then the test is one-tailed.

• True

• False

When the standard deviations are equal but unknown, a test for the differences between two population means has n − 1 degrees of freedom

• True

• False

The researcher must decide on the level of significance before formulating a decision rule.

• True

• False

A test statistic is a value computed from sample information that is used to test the null hypothesis.

• True

• False

If the null hypothesis is µ ≥ 200, then a two-tail test is being conducted

• True

• False

A null hypothesis makes a claim about a ______

• Population Parameter

• Sample Statistic

• Sample Mean

• Type II Error

What statement do we make that determines if the null hypothesis is rejected?

• Decision Rule

• Test Statistics

• Alternate Hypothesis

• Critical Value

A recent study focused on the number of times men and women send a Twitter message in a day. The sample information is summarized here.

At the 0.01 significance level, we ask if there is a difference in the mean number of times men and women send a Twitter message in a day. What is the test statistic for this hypothesis?

• t-statistic

• z-statistic

• p-statistic

• df-statistic

A recent study focused on the number of times men and women send a Twitter message in a day. The sample information is summarized here.

Assume that women are population 1 and men are population 2. The manager wants to find whether there is a difference in the mean number of times men and women send a Twitter message in a day. What will be the alternate hypothesis?

• Ho : µ1 = µ2

• Ho : µ1 ≠ µ2

• H1 : µ1 = µ2

• H1 : µ1 ≠ µ2

A recent study focused on the number of times men and women send a Twitter message in a day. The sample information is summarized here.

Assume that women are population 1 and men are population 2. The manager wants to know whether there is a difference in the mean number of times men and women send a Twitter message in a day. She has calculate the p-value, which is 0.0164. At the 0.01 significance level, what is your conclusion?

• Reject the null hypothesis and conclude the means are different.

• Reject the null hypothesis and conclude the means are the same.

• Fail to reject the null hypothesis and conclude the means are the same.

• Fail to reject the null hypothesis and conclude the means are different.