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13. Which of the following sampling methods does not lead to the samples that ca

ID: 3043042 • Letter: 1

Question

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

convenience sampling

cluster sampling

stratified sampling

systematic sampling

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

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

stratum

various strata are selected from the sample

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

stratum

None of these alternatives is correct.

2

OMG321 Quiz 1 Prof. Jian-yu Fisher Ke

15. Random samples of size 81 are taken from an infinite population whose mean and standard deviation are 200 and 18, respectively. The distribution of the population is unknown. The mean and the standard error of the mean are (assuming infinite population)

200 and 18

81 and 18

9 and 2

200 and 2

16. A population has a mean of 300 and a standard deviation of 18. A sample of 144 observations will be taken. The probability that the sample mean will be between 297 to 303 is (assuming infinite population)

0.4332

0.8664

0.9544

0.0668

Explanation / Answer

13. Convenience sample doesn't represent the population.

Option A is correct.

14. In stratified sampling, the population is first divided into strata, and then random samples are drawn from each stratum.

Option C is correct.

15. Mean = population mean = 200

Standard error = 18/sqrt(81) = 18/9 = 2

Option D is correct.

16. P(Sample mean between 297 and 303)

= P(-2 < z < 2)

= 0.9544

Option C is correct.

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