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MCQs in Statistics

There are 10 multiple choice questions but i need all work shown and explanation for answers:

1. The Central Limit Theorem says that , if n exceeds 30, a histogram of the sample will have a bell-shape, even if the population isn't normal.

A) True
B) False

2. In a sample size calculation for a mean, if the confidence level decreases, the size of the sample needed will increase.

A) True
B) False

3. The standard error of the mean decreases when the

A) sample size decreases
B) standard deviation increases if n is constant
C) standard deviation decreases and n increase
D) population size decreases

4. To estimate the average annual expenses of students on books and class materials a sample of size 36 is taken. The average is $850 and the standard deviation is $54. A 99% confidence interval for the population mean is

A) $823.72 to $876.28
B) $832.36 to $867.64
C) $826.82 to $873.18
D) $825.48 to $874.52

5. In last year's annual report, a company indicated that it had 15 regional distribution centers. This is an example of ordinal scale data.

A) True
B) False

6. Temperature ( measured in degrees Fahrenheit) is an example of ratio data.

A) True
B) False

7) If you randomly sample 50 students about their television viewing habits at one point in time, the data collected would be referred to as cross-sectional data.

A) True
B) False

8) Thirty patients are selected from a filing cabinet containing 812 patient folders by choosing every 27th patient folder. Which sampling method is this?

A) Simple random sample
B) Systematic sample
C) Stratified sample
D) Cluster sample

9) In a right -tail test, a statistician came up with a z test statistic of 1.469. What is the p-value?

A) .4292
B) .0708
C) .0874
D) .0301

10) For a one-tailed test of hypothesis for a single population mean with 13 degrees of freedom, the value of the test statistic was 1.863. The p-value is

A) between .05 and .025
B) between .10 and .05
C) greater than .10
D) less than .001

Solution Preview

Answers and Explanations:

(1) Even if the population is not normal, statistical investigations show that for sample sizes greater than 30, the sampling distribution of the sample means is normal. Therefore, Option (A).

(2) Confidence level is, in other words, how tight is the tolerance zone. Therefore, as the tolerance relaxes, the sample size required ...

Solution Summary

Answers and Explanations/Calculations are provided for all the questions.

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