Exam 8: Hypothesis Testing: Inferences About a Single Mean

When the variable under study is quantitative in nature and measured on a level that at least approximates interval characteristics,hypotheses about the value of a population mean can be tested using the one sample z test,if the population variance is known.

If N = 30,the sample mean is 12,and the estimated standard error of the mean is 2,what are the 95% confidence intervals?

A t value is analogous to a z score except that it represents the number of estimated standard errors a sample mean is from ì.

A group of 200 students takes the Kaplan course in hopes that it will improve their SAT scores above the national mean of 500 on the math section.The population standard deviation of the SAT is known to be 100.Use an alpha level of .05 when answering the following questions.The students who took the Kaplan course obtain a mean of 520 on the math SAT.Compute the one-sample z test statistic.

The _____ is a probability value determined by the experimenter to define the _____,which is the set of all scores more extreme than the critical values.

The t-distribution should be used when _____,while the z-distribution should be used when _____.

Which of the following "t statements" is the proper way to present data in an manuscript using APA format?

Which of the following accurately defines a Type II error?

Failure to reject the null hypothesis when it is false is called a:

If a researcher sets a critical z value equal to $\pm$ 1.96,then test statistics falling beyond that range _____.

What is the null hypothesis?

When a result of a statistical test is found to fall within the range of the critical values,the statistical conclusion is to ____________________.the null hypothesis.

A statistically significant result will always have important practical implications.

The null hypothesis is the hypothesis that we assume to be false for purposes of conducting a statistical test.

Increasing alpha can increase power,however the trade-off is that ____________________.is also increased.

A test statistic is the same as an ordinary descriptive statistic.

A researcher takes a very large,nationwide random sample of 7th grade students and computes a mean verbal ability score of 85.50 with a standard deviation of 8.35.From this information,she computes a standard error of the mean of 2.64.What are the upper and lower limits of the 95% confidence interval for the mean?

The hypothesis of "no difference" that is assumed to be true is called the ____________________.

Which of the following is NOT one of the conditions for using the one-sample z test?

Suppose you know that the mean score (m)on a measure of the personality trait "Openness to Experience" is 35.66 in a population of artists,with a standard deviation (s)of 13.32.Next,assume you went to Greenwich Village and gave this personality measure to a group of 10 artists.The mean in this sample was 40.33.You are interested in testing whether the 10 Greenwich Village artists were sampled from the same population described above.Calculate the test statistic for this example.