Exam 13: Students T Test for Single Samples

Which of the following are not characteristics of the t distribution?

The t test can only be applied to a nondirectional alternative hypothesis.

The t distribution is the same for all sample sizes.

The 95% confidence interval means that 95% of the time = .

A researcher believes that women today weigh less than in previous years. To investigate this belief, she randomly samples 41 adult women and records their weights. The scores have a mean of 111 lbs. and a standard deviation of 12.4. A local census taken several years ago shows the mean weight of adult women was 115 lbs. The df for determining t crit = _________.

If = 30, s = 5.2, = 28.0, s = 6.1 and N = 13, the value of the most powerful statistic to test the significance of the sample mean is _________.

When using the t test, we reject H 0 _________.

Define Cohen's d .

When df = ¥ the t distribution is identical to the z distribution.

A sample has a value of = 46, s = 8, and N = 12.

A study is conducted, and Pearson r is calculated on the sample data. Assume r = 0.77. Does this mean there is a non-zero correlation in the population? Explain.

The mean of the t distribution equals 0 for all sample sizes.

Assume that µ = 500 and s = 100. Your study shows a sample of size 22 with a mean of 530 and standard deviation of 113.

The t test requires that the sampling distribution of is normal.

Using the information in problem 26:

The 99% confidence limit is always wider than the 95% confidence interval.

If N t test, the population of raw scores should be normally distributed.

The _______ confidence interval for the population mean is always wider than the _______ confidence interval for the population mean.

Consider the following set of scores:

Generally speaking, the more confidence we have that the interval contains the population mean, the larger is the interval.