A local tennis pro-shop strings tennis rackets at the tension (pounds per square inch) requested by the customer. Recently a customer made a claim that the pro-shop consistently strings rackets at lower tensions, on average, than requested.
To support this claim, the customer asked the pro shop to string 13 new rackets at 65 psi. Suppose the two-tailed P-value for the test described above (obtained from a computer printout) is 0.09. Give the proper conclusion for the test. Use = 0.05. A) There is sufficient evidence to conclude that , the true mean tension of the rackets, is less than 65 psi.
B) Accept H0 and conclude that , the true mean tension of the rackets, equals 65 psi.
C) There is insufficient evidence to conclude that , the true mean tension of the rackets, is less than 65 psi.
D) Reject H0 and conclude that , the true mean tension of the rackets, equals 65 psi.
Q. 2A researcher wanted to determine whether women with children are more likely to develop anxiety disorders than women without children. She selected a sample of 900 twenty-year old women and followed them for a twenty-year period.
At the start of the study, none of the women had children. By the end of the study 53 of the women had at least one child. The level of anxiety of each participant was evaluated at the beginning and at the end of the study and the increase (or decrease) in anxiety was recorded. The researchers analyzed the results to determine whether there was an association between anxiety and having children. A) cohort; Individuals are observed over a long period of time.
B) cross-sectional; Information is collected at a specific point in time.
C) retrospective; Individuals are asked to look back in time.
Q. 3The ______________ probability of an outcome is obtained by dividing the number of ways an event can occur by the number of possible outcomes.
A) Classical B) Subjective C) Empirical D) Conditional
Q. 4A quiz consists of 780 true or false questions. If the student guesses on each question, what is the standard deviation of the number of correct answers?
A) 13.96424 B) 0 C) 2 D) 19.7484177
Q. 5A local eat-in pizza restaurant wants to investigate the possibility of starting to deliver pizzas. The owner of the store has determined that home delivery will be successful if the average time spent on the deliveries does not exceed 32 minutes.
The owner has randomly selected 23 customers and has delivered pizzas to their homes in order to test if the mean delivery time actually exceeds 32 minutes. Suppose the P-value for the test was found to be 0.0297. State the correct conclusion. A) At = 0.025, we fail to reject H0. B) At = 0.05, we fail to reject H0.
C) At = 0.02, we reject H0. D) At = 0.03, we fail to reject H0.
Q. 6The length of time it takes college students to find a parking spot in the library parking lot follows a normal distribution with a mean of 6.5 minutes and a standard deviation of 1 minute.
Find the probability that a
randomly selected college student will take between 5.0 and 7.5 minutes to find a parking spot in the library
lot.
A) 0.7745 B) 0.4938 C) 0.0919 D) 0.2255
Q. 7Researchers wanted to determine whether there was an association between city driving and stomach ulcers. They selected a sample of 900 young adults and followed them for a twenty-year period.
At the start of the study none of the participants was suffering from a stomach ulcer. Each person kept track of the number of hours per week they spent driving in city traffic. At the end of the study each participant underwent tests to determine whether they were suffering from a stomach ulcer. The researchers analyzed the results to determine whether there was an association between city driving and stomach ulcers. A) cohort; Individuals are observed over a long period of time.
B) cross-sectional; Information is collected at a specific point in time.
C) retrospective; Individuals are asked to look back in time.
Q. 8Determine the critical values for a two-tailed test of a population mean at the = 0.01 level of significance based on a sample size of n = 29.
A) 2.763 B) 2.756 C) 2.467 D) 2.462
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