1 A professor grades students on four tests, a term paper, and a final examination. Each test counts as 15% of the course grade. The term paper counts as 20% of the course grade. The final examination counts as 20% of the course grade. Alan has test scores of 94, 84, 88, and 96.

Alan received an 80 on his term paper. His final examination score was 84. Use the weighted mean formula to find Alan's average for the course. (Round your answer to one decimal place.)

3 A survey of 10 fast-food restaurants noted the number of calories in a mid-sized hamburger. The results are given in the table below.

515

506

503

499

497

505

457

479

463

514

Find the sample standard deviation of these data. Round to the nearest hundredth.

7 A customer at a specialty coffee shop observed the amount of time, in minutes, that each of 20 customers spent waiting to receive an order. The results are recorded in the table below.

3.2	4.1	3.7	2.5	4.7	5.1	4.5	3.4	3.5	6.2
3.6	5.0	4.6	5.0	2.9	3.4	2.3	3.9	5.4	3.0

Find the sample standard deviation of these data. Round to the nearest hundredth.

9 A recent survey by the U.S. Census Bureau determined that the median monthly housing rent was $638. If the first quartile for monthly housing rent was $499, find the percent of monthly housing rents that were the following values. (a) more than $499 % (b) less than $638 % (c) between $499 and $638%

11 A survey of 16 energy drinks noted the caffeine concentration of each drink in milligrams per ounce. The results are given in the table below.

9.1	9.0	7.5	7.8	7.9	8.8	8.8	8.8
9.0	9.1	8.3	9.2	9.0	8.3	8.8	8.8

Find the sample standard deviation of these data. Round to the nearest hundredth.

12 Consider the following. 18, 11, 15, 22, 24, 28 Compute the population standard deviation of the numbers. (Round your answer to two decimal place.) (a) Double each of your original numbers and compute the standard deviation of this new population. (Round your answer to two decimal place.) (b) Use the results of part (a) and inductive reasoning to state what happens to the standard deviation of a population when each data item is multiplied by a positive constant k. The standard deviation is multiplied by -k.The standard deviation is k. The standard deviation is multiplied by k.The standard deviation is unchanged.The standard deviation is divided by k.

15 The mean of 11 numbers is 50. Removing one of the numbers causes the mean to decrease to 44. What number was removed?

16 Find the range, the standard deviation, and the variance for the given samples. Round non-integer results to the nearest tenth.68, 67, 63, 70, 86, 85, 57, 93, 61

20 For the first half of a baseball season, a player had 94 hits out of 275 times at bat. The player's batting average was

94

275

0.342.

During the second half of the season, the player had 55 hits out of 282 times at bat. The player's batting average was

55

282

0.195.

(Round your answers to three decimal places.)(a) What is the average (mean) of 0.342 and 0.195? (b) What is the player's batting average for the complete season? (c) Does the answer in part (a) equal the average in part (b)? Yes / No

21 The following tables list the ages of female and male actors when they starred in their award-winning Best Actor performances. (A graphing calculator is recommended.)Ages of Best Female Actor Award Recipients

60 68 73 70 22 29 44 40 78 34 28 74 40 73 41 78 72 73 60 39 80 61 29 44 55 42 61 63 40 74 76 47 78 52

Ages of Best Male Actor Award Recipients

68 57 76 38 43 57 47 60 32 33 76 66 52 55 38 57 38 64 43 51 55 44 44 60 50 75 64 58 56 71 69 33 71 39

(a) Find the sample standard deviation of the ages of the female recipients. Round each result to the nearest tenth.

(b) Find the sample standard deviation of the ages of the male recipients. Round each result to the nearest tenth.

22 Consider the following. 34, 6, 22, 17, 19 Compute the population standard deviation of the numbers. (Round your answer to one decimal place.)

(a) Add a nonzero constant c to each of your original numbers and compute the standard deviation of this new population. (Round your answer to one decimal place.) (b) Use the results from part (a) and inductive reasoning to state what happens to the standard deviation of a population when a nonzero constant c is added to each data item. The standard deviation becomes c.The standard deviation decreases by c. The standard deviation becomes 0.The standard deviation remains the same.The standard deviation increases by c.

24 On a reading test, Shaylen's score of 455 was higher than the scores of 4262 of the 7248 students who took the test. Find the percentile, rounded to the nearest percent, for Shaylen's score.