Q1. 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 94 lbs. is:
A. 15.87%
B. 84.13%
C. 34.13%
D. 56.36%
E. 16.87%
Q2 The internal auditing staff of a local manufacturing company performs a sample audit each quarter to estimate the proportion of accounts that are delinquent more than 90 days overdue. The historical records of the company show that over the past 8 years 13 percent of the accounts are delinquent. For this quarter, the auditing staff randomly selected 250 customer accounts. What is the probability that no more than 40 accounts will be classified as delinquent?
A. 42.07%
B. 92.07%
C. 7.93%
D. 40.15%
E. 90.15%
Q3. If we have a sample size of 100 and the estimate of the population proportion is 0.10, the mean of the sampling distribution of the sample proportion is:
A. 0.009
B. 0.10
C. 0.03
D. 0.90
E. 0.09
Q4. Consider a sampling distribution formed based on n = 10. The standard deviation of the population of all sample means is ______________ more than the standard deviation of the population of individual measurements σ.
A. Always
B. Sometimes
C. Never
Q5. 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 be less than 84 lbs. is:
A. 16.87%
B. 93.32%
C. 43.32%
D. 6.68%
E. 84.13%
Q6. If a population distribution is known to be normal, then it follows that:
A. The sample mean must equal the population mean
B. The sample mean must equal the population mean for large samples
C. The sample standard deviation must equal the population standard deviation
D. All of the above
E. None of the above
Q7. According to a hospital administrator, historical records over the past 10 years have shown that 20% of the major surgery patients are dissatisfied with after-surgery care in the hospital. A scientific poll based on 400 hospital patients has just been conducted. Sixty-four (64) patients indicated that they were dissatisfied with the after surgery care. What are the mean and the standard deviation of the sampling distribution of p?
A. 16% and .034%
B. 20% and 1.83%
C. 20% and 2%
D. 20% and .034%
E. 20% and 16%