1. A researcher wants to know whether people who regularly listen to radio talk shows are more or less likely to vote in national elections than people in general.
a. State the research hypothesis and null hypothesis
– Research = People who listen to radio talk shows regularly are more likely to vote in a national election than people in general.
– Null = There is no relationship between people who listen to radio talk shows and vote, and those who do not listen to talk shows and vote.
Would the researchers use a one- or two-tailed Z test?
2. The general population (Population 2) has a mean of 30 and a standard deviation of 5, and the cutoff Z score for significance in a study involving one participant is 1.96. If the raw score obtained by the participant is 45, what decisions should be made about the null and research hypotheses?
– z = (X-Mu)/SD
z = (45-30)/5 = + 3
Since the z-score (+3) of the concerned raw score of the participant > 1.96, the null hypothesis will be rejected. In other words, it can be said that there is sufficient evidence to reject the null hypothesis
The alternative hypothesis can be accepted
It can be inferred that there is significant difference between the raw score and population mean
3. One hundred people are included in a study in which they are compared to a known population that has a mean of 73, a standard deviation of 20, and a rectangular distribution.
a. μM = ___73_______.
b. σM = ____20______.
c. The shape of the comparison distribution is ___rectangular_______.
d. If the sample mean is 75, the lower limit for the 99% confidence interval is ____69.75______.
e. If the sample mean is 75, the upper limit for the 99% confidence interval is ____80.25______.
f. If the sample mean is 75, the lower limit for the 95% confidence interval is _____71.03_____.
g. If the sample mean is 75, the upper limit for the 95% confidence interval is ____78.97______.