1. Since the central limit theorem states that a normal distribution of sample means will result from virtually any underlying distribution, all of the following are true except ________.

• approximately 75% of the sample means will be between ±2 standard errors of μ
• approximately 99% of the sample means will be between ±3 standard errors of μ
• approximately 95% of the sample means will be between ±2 standard errors of μ
• approximately 68% of the sample means will be between ±1 standard errors of μ

Question 2. The t-distribution is very much like the standard normal distribution except that the t-distribution ________.

• has a smaller variance
• has a smaller standard deviation
• is bi-symmetrical
• has a larger variance

Question 3. Find the standard error of the mean when the population standard deviation is 2.4 and a sample of size 36 is taken.

• 4.03
• 0.6
• 14.4
• 0.4

Question 4. The finite population correction factor (FPC) is found by ________.

Question 5. A point estimate ________.

• has a known measurement error
• can be found by dividing the population parameter by the sample size
• accurately estimates the population parameter
• is a sample-based estimate of a population parameter

Question 6. In simple random sampling ________.

• every subset has an equal chance of being selected
• sampling is taken from the most easily available segments of the population
• every nth item is selected from the population
• weights are assigned to each value based on the probability that it will be included in the sample

Question 7. Peak Previously Played Picks buys and sells used sports equipment. For the past year, the mean purchase of used sports equipment was $36 with a standard deviation of $8. Using the Microsoft Excel function NORM.DIST, find the probability that the next person who comes in to sell used equipment will be paid less than $20.

• 2.28%
• 69.15%
• 100.00%
• 97.73%

Question 8. The two most commonly used types of estimates in statistics are ________.

• cluster intervals and standard estimates
• unbiased estimator and standard distribution
• point estimates and confidence intervals
• sampling estimates and central limit interval

Question 9. A finite population correction factor should be used to adjust the margin of error when the sample taken is larger than ________ of the entire population.

• 10%
• 1%
• 5%
• 50%

Question 10. The basic difference between subjective and probabilistic sampling methods is whether ________.

• the data collected are qualitative or quantitative
• a random procedure is used or not
• a person or object is being sampled
• actual measurements are being taken or estimates are being used

Question 11. From a sample of 25 items, a sample standard deviation of 4.56 ounces was just measured. What value should be used for the population standard deviation?

• 0.91 ounces
• 4.56 ounces
• none, since the population standard deviation cannot be estimated
• 0.18 ounces

Question 12. A major consumer products company wants to measure the quality of the packaging of their products on the store shelves. In a chain grocery store, all of the packages of a 15-ounce Wild Berry shampoo and all of the packages of a 4-ounce Man-O-Manly deodorant are sampled. What sampling method is being used for this sampling plan?

• cluster sampling
• simple random sampling
• continuous sampling
• protracted random sampling

Question 13. Which of the following is a subjective sampling method?

• cluster sampling
• judgment sampling
• systematic sampling
• stratified sampling

Question 14. Find the standard error of the mean when the population standard deviation is 160 and a sample of size 16 is taken.

• 0.14
• 40
• 1.26
• 10

Question 15. For a 95% confidence interval for a population mean, there is ________.

• a 95% confidence that the center of the interval is the true population mean
• a 95% probability that the true population mean will fall in that range of values
• a 95% probability that the population mean comes from a normal distribution
• a 95% confidence that the sample mean is the true population mean

Question 16. What is the value of the finite population correction factor when a sample size of 125 was taken from a finite population of 500?

• 0.75
• 1.15
• 0.87
• 1.33

Question 17. A sampling plan ________.

• states the design quality for production managers
• describes the characteristics of a population
• is used when the product or process is not well understood
• describes the approach that will be used to obtain samples from a population

Question 18. For a sample size of 172, the degrees of freedom are ________.

• 172
• 171
• 13.11
• 173

Question 19. Cluster sampling ________.

• is used with populations that are naturally divided into subsets
• requires difficult sorting of the population data into specific samples
• consists of a census of selected population subgroups
• ensures each individual item has an equal chance of selection

Question 20. Peak Previously Played Picks buys and sells used sports equipment. For the past year, the mean purchase of used sports equipment was $36 with a standard deviation of $8. Using the Microsoft Excel function NORM.DIST, find the probability that the next person who comes in to buy used equipment will pay more than $40.

• 30.85%
• 69.15%
• 24.20%
• 95.60%