. A waiter kept track of how much he received in tips from each table he served over the course of the past year. The distribution of these tip amounts is approximately normal with a mean of $6.50 and a standard deviation of $2.10. The top 20% of his tips are greater than what amount? (A) $2.52 (B) $3.81 (C) $7.80 (D) $8.27 (E) $9.19

Which of the following is an example of doing inferential statistics? You calculate the average grade on an exam in a class of 5th grade math students to see if they did better or worse than last year. You lookup the median and the standard deviation of the age for the U.S. population from U.S. Census data. You use a sample of homes in Rancho Cucamonga to draw a conclusion about the mean home price for all Rancho Cucamonga homes. You compare the distributions of scores for two Social Science 10 classes to see which class did better on the exam.

Answer.

Suppose annual salaries for sales associates from Hayley's Heirlooms have a bell-shaped distribution with a mean of $32,500 and a standard deviation of $2,500.The z-score for a sales associate from this store who earns $37,500 is _____.   a. .92     b. 37.5     c. −2     d. 2