Exam 9: Hypothesis Tests

A machine is designed to fill toothpaste tubes, on an average, with 5.8 ounces of toothpaste.The manufacturer does not want any underfilling or overfilling.The correct hypotheses to be tested are

Two thousand numbers are selected randomly; 960 are even numbers. a. State the hypotheses to determine whether the proportion of odd numbers is significantly different from 50%. b. Compute the test statistic. c. At the .10 level of significance using the p-value approach, test the hypotheses.

Read the z statistic from the normal distribution table and choose the correct answer.For a two-tailed test using α = .0802, z =

The p-value

For a lower tail hypothesis test with a sample size of 13 and a .10 level of significance, the critical value of the test statistic t is

The probability of committing a Type I error when the null hypothesis is true as an equality is

When the following hypotheses are being tested at a level of significance of α ​ H₀: μ 500 H_a: μ < 500 ​ The null hypothesis will be rejected, if the p-value is

Two approaches to drawing a conclusion in a hypothesis test are ​

A Type I error is committed when​

Read the t statistic from the t distribution table and choose the correct answer.For a one-tailed test (upper tail) with a sample size of 16 and at the .10 level, t =

The probability of making a Type I error is denoted by

Some people who bought X-Game gaming systems complained about having received defective systems.The industry standard for such gaming systems has been 98% non-defective systems.In a sample of 120 units sold, 6 units were defective. a. Compute the proportion of defective items in the sample. b. b. Compute the standard error of . c. At a 5% level of significance using the critical value approach, test to see if the percentage of defective systems produced by X-Game has exceeded the industry standard. d. Show that the p-value approach results in the same conclusion as that of part

What type of error occurs if you fail to reject H₀ when, in fact, it is not true?

A student believes that no more than 20% (i.e., 20%) of the students who finish a statistics course get an A.A random sample of 100 students was taken.Twenty-four percent of the students in the sample received 'A's. a. State the null and alternative hypotheses. b. Using the critical value approach, test the hypotheses at the 1% level of significance. c. Using the p-value approach, test the hypotheses at the 1% level of significance.

A random sample of 25 students selected from the student body of a large university had an average age of 25 years and a standard deviation of 2 years.We want to determine if the average age of all the students at the university is significantly more than 24.Assume the distribution of the population of ages is normal.The p-value is between

Read the z statistic from the normal distribution table and choose the correct answer.For a one-tailed test (upper tail) using α = .0721, z =

A random sample of 25 students selected from the student body of a large university had an average age of 25 years and a standard deviation of 2 years.We want to determine if the average age of all the students at the university is significantly more than 24.Assume the distribution of the population of ages is normal.The test statistic is

The average manufacturing work week in metropolitan Chattanooga was 40.2 hours last year.It is believed that the recession has led to a reduction in the average work week.To test the validity of this belief, the hypotheses are

A random sample of 100 people was taken.Eighty-five of the people in the sample favored Candidate A.We are interested in determining whether or not the proportion of the population in favor of Candidate A is significantly more than 80%.At the .05 level of significance, it can be concluded that the proportion of the population in favor of candidate A is

In the past, the average age of employees of a large corporation has been 40 years.Recently, the company has been hiring older individuals.In order to determine whether there has been an increase in the average age of all the employees, a sample of 64 employees was selected.The average age in the sample was 45 years with a standard deviation of 16 years.Let α = .05. a. State the null and the alternative hypotheses. b. Compute the test statistic. c. Using the p-value approach, test to determine whether or not the mean age of all employees is significantly more than 40 years.