Download Hypothesis Quiz with Answers - Statistics for Engineering | STAT 4706 and more Quizzes Statistics in PDF only on Docsity! Question Science Magazine reported that the mean listening time of 7-month-old infants exposed to a three-syllable sentence (e.g., "I love you") is 9 seconds. A sample of 50 infants of the same age was tested at a hospital in Houston and found the average time to be 8 seconds. What is the null hypothesis? Answer Ηο: µ=9 Ηο: µ=8 Η1: µ>9 none of the above. Correct Feedback Good job! Incorrect Feedback The null hypothesis, denoted Ho, uses the specified value of the population mean, which in this case is 9. The sample mean was 8. In this course, the null hypothesis always uses the equal sign. Question Set up the alternative hypothesis to test if the population mean Post-Tramatic Stress Disorder Test for WWII POW survivors is less than 16. Answer H1: µ = 16 H1: µ does not equal 16 H1: µ > 16 H1: µ< 16 Correct Feedback Good Job! Incorrect Feedback The statement says to test if the value is less than 16, so the last choice is correct. Question You are instructed to conduct a test to see whether the mean pouring temperature differs from the target setting of 20 degrees by taking a sample of 50 parts. What is the alternative hypothesis? Answer H1: µ > 20 H1: µ does not equal 20 H1: µ < 20 H1: µ = 20 Correct Feedback Good Job! Incorrect Feedback The information given does not specify a direction, so we use not equal to in the alternative hypothesis. Question When computing a test for the variance, what parameter is used in the null and alternative hypotheses? Answer µ s σ2 σ Correct Feedback Good Job! Incorrect Feedback The population variance is represented by σ2. Question What parameter is used in the null and alternative hypotheses when testing for the population mean when the population variance is unknown? Answer σ2 µ x-bar t Correct Feedback Good Job! Incorrect Feedback When testing for the population mean, you always use µ, whether you know the population variance or not. Question A two-tailed hypothesis test has what symbol in the alternative hypothesis? Answer = not equal to > < Correct Feedback Good Job! Incorrect Feedback A two-tailed test means a direction is not specified, so we use the "not equal to" symbol. Question A cable company want you to conduct a test to see if the proportion of its cable subsribers that have complaints against the company is less than .13. What is the null hypothesis? Answer p = .13 p-hat = .10 p < .10 None of the above. Correct Feedback Good Job! Incorrect Feedback The hypotheses are always in terms of parameters, in this case, p. In this course, the null hypothesis is always with an = sign. Question A cable company want you to conduct a test to see if the proportion of its cable subsribers that have complaints against the company is less than .13. What is the alternative hypothesis? Answer p-hat < .13 p-hat does not equal .13 p < .13 None of the above. Correct Feedback Good Job! Incorrect Feedback The hypotheses are always in terms of a parameter, in this case, p. The question specifies a direction of less than, so a less than sign is appropriate in the alternative hypothesis.
