Question

10. If 12.1 percent of her students failed the course and received F's, what is the maximum score among those who received an F?

a. 63.1

b. 64.3

c. 65.4

d. 66.3

11. A subset of a population selected to represent the population is

a. a subset

b. a small population

c. a sample

d. a parameter

12. The phenomenon that the sampling distribution of the sample mean can be approximated by a normal distribution as the sample size become large is called

a. the neutral theorem

b. the sampling theorem

c. the central limit theorem

d. the normal distribution theorem

13. Which of the following sampling methods does not lead to the samples that can represent population?

a. convenience sampling

b. cluster sampling

c. stratified sampling

d. systematic sampling

14. Stratified random sampling is a method of selecting a sample in which

a. the sample is first divided into strata, and then random samples are taken from each stratum

b. various strata are selected from the sample

c. the population is first divided into strata, and then random samples are drawn from each stratum

d. None of these alternatives is correct

Answer 1

Answer 10: Option D (66.3)

Given Mean = 78

SD = 10

Let X be the maximum score among those who receive F

z = (X - Mean)/SD

z = (X-78)/10

P(Z<(X-78)/10) = 0.121

Based on z distribution table we find that z score corresponding to probablity of 0.121 is -1.17 (Screenshot attached)

Therefore,

-1.17 = (X-78)/10

X = 78 - 1.17*10

X = 66.3

Answer 11: Option C (A Sample)

Reason: In Statistics, sample refers to a set of data collected from a larger set called population.

Answer 12: Option C (The Central Limit Theorm)

Reason: The Central Limit Theorem states that the sampling distribution of the sampling means approaches a normal distribution as the sample size gets larger — no matter what the shape of the population distribution. This fact holds especially true for sample sizes over 30.

Answer 13: Option A (Convenience sampling)

Reason: Convenience sampling is a type of non-probablity sampling

Answer 14: Option C (The population is first divided into strata, and then random samples are drawn from each stratum)

Reason: Stratified sampling is a probability sampling technique wherein the researcher divides the entire population into different subgroups or strata, then randomly selects the final subjects proportionally from the different strata.