Quiz 7

A researcher selects a sample of 25 participants from a population with a mean of 10 and a standard deviation of 5. What is the probability of selecting a sample mean that is at least two standard deviations larger than the population mean? A. .0228 B. .4772 C. .9772 D. equal to the probability of selecting a sample mean that is at least two standard deviations below the mean

B. .4772

A sample of 25 participants where the population mean was 10 and standard deviation of 5 completed a word recall test. What is the probability of obtaining a sample mean that is at least two standard deviations larger than the population mean? A. .0228 B. .4772 C. .9772 D. equal to the probability of obtaining a sample mean that is at least two standard deviations below the mean

B. .4772

A researcher selects a sample of 121 participants from a population with a mean of 32 and a standard deviation of 22. What is the standard error of the mean? A. 32 B. 2.0 C. 0.5 D. there is not enough information to answer this question.

B. 2.0

A researcher states that a sample of 100 shoppers spend 112 ± 40 (M ± SEM) dollars on groceries each week. Which value is the standard error of the mean? A. 112 B. 40 C. 100 D. the standard error of the mean is not reported in the article

B. 40

On average the sample mean will equal the population mean, and the sample mean is an unbiased estimator. A. True B. False

A. True

According to the central limit theorem, as the number of samples in the sampling distribution increases, the sampling distribution of sample means selected at random from that population will A. Approach the shape of a normal distribution B. Be asymmetrical C. Not be based on theory D. Be nonmodal

A. Approach the shape of a normal distribution

If a researcher selects a sample of 36 participants from a population with a variance of 16, then the standard error of the mean will be 2.0. A. True B. False

B. False

A distribution of all sample means or sample variances that could be obtained in samples of a given size from the same population is called A. a conditional procedure B. a samping distribution C. sampling without replacement D. random sampling

B. a sampling distribution

A researcher selects from a participant pool of 4 males and 6 females. He determines that the probability of selecting 2 female participants is p = .30. Based on this probability, what strategy did the researcher use to sample participants. A. sampling with replacement B. sampling without replacement

B. sampling without replacement

A researcher selects a sample of 25 participants from a population with a mean of 10 and a standard deviation of 5. What is the probability of selecting a sample mean equal to at least 12? A. less than 1% B. greater than 50% C. about the same as selecting a sample mean that is at least equal to the population mean D. equal to the probability of selecting a sample mean that is smaller than 8

C. about the same as selecting a sample mean that is at least equal to the population mean