STATISTICS AND PROBABILITY 3rd Quarter Review

Consider the population consisting of values {2, 4, 6}. List all the possible samples of size 2 which can be drawn with replacement.

• {2,4,6}

• (4,2),(4,4),(4,6),(6,2),(6,4),(6,6)

• {(2,2),(2,4),(2,6) ,(4,2),(4,4),(4,6)}

• {(2,2),(2,4),(2,6),(4,2),(4,4),(4,6),(6,2),(6,4),(6,6)}

Which sample size will give a smaller standard error of the mean?

• 35

• 18

• 12

• 9

What do you call a variable where the information or data can take countable values?

• Continuous variable

• Discrete variable

• Quantitative variable

• Qualitative variable

What can we generate if we take the square root of variance?

• Mean

• Median

• Probability value

• Standard deviation

Which of the following statements best describe the expected value of a discrete random variable?

• It is the simple average of all possible outcomes.

• It is the geometric average of all possible outcomes.

• It is the weighted average over all possible outcomes.

• It is the complex average of all possible outcomes in the distribution.

As the sample size n increases, the standard deviation of the sampling distribution __________.

• A. increases

• B. decreases

• C. stays the same

• D. nothing happened

Find P (0 ≤ Y ≤ 3)

• 9/10

• 4/5

• 1/2

• 3/10

Given μ=15, s=5, and n=16. This is an example of the sampling distribution of the sample mean for a normal population when the population variance is _______.

• A. unknown

• B. known

• C. large

• D. small

This distribution is used to estimate population parameters when the population variance is unknown, and the sample size is less than 30.

• A. Z-Distribution

• B. t-Distribution

• C. Chi-Square Distribution

• D. Pearson Correlation Coefficient

The probabilities that a customer buys 5, 8, 9, 12, and 15 items in a grocery store are 0.06, 0.14, 0.32, 0.28, and 0.20 respectively. Which probability distribution represents the given problem?

• X 5 8 9 12 15

  P(X) 0.06 0.14 0.2 0.28 0.32

• X 5 8 9 12 15

  P(X) 0.06 0.14 0.2 0.28 0.32

• X 5 8 9 12 15

  P(X) 0.06 0.14 0.32 0.28 0.20

• X 5 8 9 12 15

  P(X) 0.32 0.28 0.2 0.14 0.06