Exam 6: Hypothesis Tests With Means of Samples

In survey work and polls, the absolute number of people polled is not very important, but what maters very much are the methods of sampling and estimating error. (True or False)

Do corporate executives who exercise regularly score lower than corporate executives in general on a scale of stress symptoms? For corporate executives in general, the average on this test is 80 with a standard deviation of 12. The distribution is normal. A researcher measured 20 exercising executives and found them to have a mean score of 72. Is this difference significant at the .05 level? a. Use the five steps of hypothesis testing. b. Figure the confidence limits for the 95% confidence interval. c. Explain the logic of what you did to a person who is unfamiliar with hypothesis testing involving a sample of more than one individual.

For the following question(s): A researcher is interested in whether the color of an animal's surroundings affects learning rate. She tests 16 rats in a box with colorful wallpaper. Assume that it is known that the average rat can learn to run this particular maze (in a box without any special coloring)in 25 trials, with a variance of 64; the distribution is normal. The mean number of trials to learn the maze for the group with the colorful wallpaper is 11. -What is the shape of the distribution of means?

Other names for the standard error include the standard deviation of the distribution of means and the standard error of the mean. (True or False)

95% and 99% are common ranges for __________.

The __________ of a distribution of means equals the __________ of the population divided by the number of individuals in the sample. (Use the same word in both places.)

The __________ are the upper and lower ends of the confidence interval.

"Population SD²_M" stands for __________.

The variance of the distribution of means = __________.

For a 99% confidence interval, you use the Z scores for the middle 99% of the normal curve, which comes out to:

The standard deviation of a distribution of means is:

The variance of a distribution of means equals the variance of the population of individuals divided by the __________.

How do you find the Z score for a sample's mean on the distribution of means?

The Z score of the sample mean on the distribution of means is:

The variance of a distribution of means of samples of more than one is:

The standard deviation of a distribution of means is the square root of the variance of __________.

In a research article involving a sample and a known population mean, frequently reported statistics would include:

A region of scores estimated to include a population parameter such as the population mean is called:

A distribution of means will be less spread out than the population of individuals from which the samples are taken because:

A researcher can use confidence intervals to do hypothesis testing. If the confidence interval does not include the mean of the null hypothesis distribution, then the result is significant. (True or False)