Ashford University BUS 308 statistics for managers Week 3 Quiz (Graded)

1. Question : When the sample size and sample standard deviation remain the same, a 99% confidence interval for a population mean, µ will be _____ the 95% confidence interval for µ. Student Answer: wider than narrower than equal to Points Received: Comments: 2. Question : A sample statistic is an unbiased point estimate of a population parameter if the mean of the population of all possible values of the statistic equals the population parameter. Student Answer: True False Points Received: Comments: 3. Question : When the sample size and the sample proportion remain the same, a 90% confidence interval for a population proportion p will be ______ the 99% confidence interval for p. Student Answer: wider than narrower than equal to Points Received: Comments: 4. Question : A manufacturing company measures the weight of boxes before shipping them to the customers. If the box weights have a population mean and standard deviation of 90 lbs and 24 lbs respectively, then, based on a sample size of 36 boxes, the probability that the average weight of the boxes will be less than 84 lbs is Student Answer: 16.87%. 93.32%. 43.32%. 6.68%. 84.13%. Points Received: Comments: 5. Question : When the population is normally distributed and population standard deviation ? is unknown, then for any sample size n, the sampling distribution of is a t distribution. Student Answer: True False Points Received: Comments: 6. Question : The central limit theorem states that as sample size increases, the population distribution more closely approximates a normal distribution. Student Answer: True False Points Received: Comments: 7. Question : The results of a scientific poll showed that 64 out of 400 patients at a certain hospital are not satisfied with the care they received in the hospital after major surgery. A consumer advocate claims that 20% of the major surgery patients at the hospital are dissatisfied with after-surgery care. If the advocate’s claim is true, what is the probability that 64 or fewer of 400 randomly selected patients at the hospital would say they are dissatisfied with the after-surgery care. Student Answer: 47.72% 2.28% 97.72% 95.44% 4.56% Points Received: Comments: 8. Question : If the population proportion is .4 with a sample size of 20, then is this sample large enough so that the sampling distribution of is a normal distribution. Student Answer: True False Points Received: Comments: 9. Question : When a confidence interval for a population proportion is constructed for a sample size n = 100 and the value of, p = .4 the interval is based on the Student Answer: z distribution. t distribution. Exponential distribution. Poisson distribution. None of the above. Points Received: Comments: 10. Question : When the population is normally distributed, population standard deviation ó is unknown and the sample size is n = 15, the confidence interval for the population mean µ is based on Student Answer: the z (normal) distribution. the t distribution. the Binomial distribution. the Poisson Distribution. None of the above. Points Received: