In how many ways can we choose 3-numbers (with replacement) from the set {1, 3,
ID: 3238465 • Letter: I
Question
In how many ways can we choose 3-numbers (with replacement) from the set {1, 3, 5} a). 81 b) 27 c) 9 d) 1 If the mean height of men is 70 inches and variance = 25, then 95% of all men will have height: a) between 65 and 75 b) between 60 and 80 c) between 45 and 95 d) between 45 and 80 If data values in one random sample can be paired with data values in another, the samples are: a) Dependent b) Independent c) Identical d) Unmatched A box contains RED and BLUE balls. The event of choosing a RED ball or choosing a BLUE ball are: a) correlated b) mutually exclusive c) independent d) dependentExplanation / Answer
Answers
15. b) 27
Hint: Number of ways we can choose 3 numbers = 3 * 3 * 3 = 27
16. b) between 60 and 80
Hint: 95% of all men will have height within 2 standard deviations of the mean
Here = 70, 2 = 25, = 25 = 5
– 2 = 70 – (2 * 5) = 60
+ 2 = 70 + (2 * 5) = 80
17. a) Dependent
Hint: If data values in random sample can be paired with data values in another, then the sample is a paired sample or dependent sample.
18. c) independent
Hint: Probability of choosing a red ball does not affect the probability of choosing a blue ball. Hence the events are independent.