Exam 10: One-Sample Tests of Hypothesis

A manufacturer claims that less than 1% of all his products do not meet the minimum government standards.A survey of 500 products revealed ten did not meet the standard.What is your decision if the z-statistic is -1.96 and the level of significance is 0.01? ________________

A manufacturer claims that less than 1% of all his products do not meet the minimum government standards.A survey of 500 products revealed ten did not meet the standard.What is the critical value if $\alpha$ = .01? _____________

What is another name for the level of risk in hypothesis testing? __________________

The average cost of tuition,room and board at small private liberal arts colleges is reported to be $8,500 per term,but a financial administrator believes that the average cost is higher.A study conducted using 350 small liberal arts colleges showed that the average cost per term is $8,745 with a standard deviation of $1,200.Let = 0.05.What are the null and alternative hypotheses for this study?

A random sample of size 15 is selected from a normal population.The population standard deviation is unknown.Assume that a two-tailed test at the 0.10 significance level is to be used.For what value of t will the null hypothesis not be rejected?

If 20 out of 50 students sampled live in a college dormitory,what is the estimated proportion of students at the University living in a dormitory?

In hypothesis testing,what is the level of significance?

What do we call a statement about the value of a population parameter? _________________

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

When the population standard deviation is unknown,the test statistic used to test a hypothesis is the Student's t distribution.

A restaurant that bills its house account monthly is concerned that the average monthly bill exceeds $200 per account.A random sample of twelve accounts is selected,resulting in a sample mean of $220 and a standard deviation of $12.The t-test is to be conducted at the 5% level of significance.This is an example of what type of test? _______________________

For a hypothesis test with an alternative hypothesis: µ > 6,700,where is the rejection region for the hypothesis test located?

As the sample size increases,the curve of the t-distribution approaches the ______________________________.

For a one-tailed test using the 0.05 level of significance,the critical value for the z test is 1.645,but for t it is 1.96.

A nationwide survey of college students was conducted and found that students spend two hours per class hour studying.A professor at your college wants to determine whether the time students spend at your college is significantly different from two hours.A random sample of fifteen statistics students is carried out and the findings indicate an average of 1.75 hours with a standard deviation of 0.24 hours.The t-test is to be conducted at the 5% level of significance.This is an example of what type of test? _________________________

The first step in testing a hypothesis is to state the decision rule.

A manufacturer claims that less than 1% of all his products do not meet the minimum government standards.A survey of 500 products revealed ten did not meet the standard.What is your decision if the z-statistic is -2.58 and the level of significance is 0.02? _____________________________

The mean length of a small counter balance bar is 43 millimeters.There is concern that the adjustments of the machine producing the bars have changed.Test the claim at the 0.02 level that there has been no change in the mean length.The alternate hypothesis is that there has been a change.Twelve bars (n = 12)were selected at random and their lengths recorded.The lengths are (in millimeters)42,39,42,45,43,40,39,41,40,42,43 and 42.The mean of the sample is 41.5 and the standard deviation 1.784.Computed t = -2.913.Has there been a statistically significant change in the mean length of the bars?

What is a ratio,fraction or percent of the sample or the population that has a particular trait called? ______________________

An alternate hypothesis is a statement about a population parameter that is accepted when the null hypothesis is rejected.