Question

10. In a recent study on world​ happiness, participants were asked to evaluate their current lives on a scale from 0 to​ 10, where 0 represents the worst possible life and 10 represents the best possible life. The responses were normally​distributed, with a mean of 5.8 and a standard deviation of 2.3.

A. The probability that a randomly selected study​ participant's response was less than 4 is __.

B.The probability that a randomly selected study​ participant's response was between 4 and 6 is __.

C. The probability that a randomly selected study​ participant's response was more than 8 is __.

​D.  Identify any unusual events. Explain your reasoning. Choose the correct answer below.

A.The event in part left parenthesis a right parenthesis(a) is unusual because its probability is less than 0.05.

B.The events in parts left parenthesis a right parenthesis and left parenthesis c right parenthesis(a) and (c) are unusual because their probabilities are less than 0.05.

C. There are no unusual events because all the probabilities are greaterThere are no unusual events because all the probabilities are greater than 0.05.

D. The events in parts left parenthesis a right parenthesis comma left parenthesis b right parenthesis comma and left parenthesis c right parenthesis are unusual because all of their probabilities areThe events in parts (a), (b), and (c) are unusual because all of their probabilities are less than 0.05.

11. Use the standard normal table to find the​ z-score that corresponds to the cumulative area 0.6312. If the area is not in the​ table, use the entry closest to the area. If the area is halfway between two​ entries, use the​ z-score halfway between the corresponding​ z-scores.

z=__.

12. Use the standard normal table to find the​ z-score that corresponds to the given percentile. If the area is not in the​ table, use the entry closest to the area. If the area is halfway between two​ entries, use the​ z-score halfway between the corresponding​ z-scores. If​ convenient, use technology to find the​ z-score.

P15

The​ z-score that corresponds to P15 is __.

Answer 1