Exam 9: Hypothesis Tests About the Mean and Proportion

In a hypothesis test,the probability of committing a Type I error is called the:

Use the following to answer questions : The director of a radio broadcast company wants to determine whether the mean length of commercials on his station is equal to 24 seconds.A sample of 41 commercials had a mean life of 26.90 seconds and a standard deviation of 7.88 seconds.The significance level is 5%. -Should you reject or fail to reject the null hypothesis in this test? (State your answer as "reject" or "fail to reject",but don't include the quotation marks.)

Use the following to answer questions : The director of a radio broadcast company wants to determine whether the mean length of commercials on his station is equal to 24 seconds.A sample of 41 commercials had a mean life of 26.90 seconds and a standard deviation of 7.88 seconds.The significance level is 5%. -What is the value of the test statistic,t,rounded to three decimal places?

Use the following to answer questions : In a hypothesis test with hypotheses and ,a random sample of size 481 produced a sample proportion of 0.4350.The test is to be made at the 5% significance level. -What is the p-value for this hypothesis test,rounded to four decimal places?

For a one-tailed test,the p-value is:

Use the following to answer questions : In a hypothesis test with hypotheses and ,a random sample of 16 elements selected from the population produced a mean of 91.9 and a standard deviation of 4.9.The test is to be made at the 2% significance level.Assume the population is normally distributed. -What is the value of the test statistic,t,rounded to three decimal places?

Use the following to answer questions : A researcher wants to test if the mean price of houses in an area is greater than $145,000.A random sample of 35 houses selected from the area produces a mean price of $149,700.Assume that $13,100,and that the test is to be made at the 1% significance level. -Should you reject or fail to reject the null hypothesis in this test? (State your answer as "reject" or "fail to reject",but don't include the quotation marks.)

A researcher wants to test if elementary school children spend less than 30 minutes per day on homework.The null hypothesis for this example will be that the population mean is:

Which of the following statements describes a Type II error in hypothesis testing?

Use the following to answer questions : A researcher wants to test if the mean price of houses in an area is greater than $145,000.A random sample of 35 houses selected from the area produces a mean price of $149,700.Assume that $13,100,and that the test is to be made at the 1% significance level. -What is the value of the test statistic,z,rounded to three decimal places?

Suppose that the batting average for all major league baseball players after each team completes 100 games through the season is 0.248 and the standard deviation is 0.034.The null hypothesis is that American League infielders average the same as all other major league players.A sample of 46 players taken from the American League reveals a mean batting average of 0.255.What is the value of the test statistic,z (rounded to two decimal places)?

For a two-tailed test,the p-value is:

Use the following to answer questions : A researcher wants to test if the elementary school children spend less than 30 minutes per day on homework.A random sample of 64 children from the school shows that they spend an average of 24.5 minutes per day on homework.Assume that 15.3 minutes,and that the test is to be made at the 1% significance level. -What is the value of the test statistic,z,rounded to three decimal places?