26 The mean of 11 numbers is 49. Removing one of the numbers causes the mean to decrease to 44. What number was removed?

27 During a 12-hour period, the temperature in a city dropped from a high of 66F to a low of 21F. What was the range of the temperatures during this period?

28 Find the standard deviation, and the variance for the given samples. Round non-integer results to the nearest tenth.55, 98, 49, 63, 91, 83, 69, 66, 84

29 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	3.8	2.3	4.8	5.2	4.5	3.6	3.5	6.3
3.6	4.8	4.5	5.0	2.7	3.6	2.1	3.8	5.4	2.9

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

30 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

507

503

499

495

507

458

478

463

514

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

31 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	9.1	7.5	7.8	7.7	8.7	8.9	8.9
8.9	9.1	8.3	9.0	9.0	8.2	8.8	8.8

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

32 Consider the following. 15, 18, 27, 4, 14, 10

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 k.

The standard deviation is multiplied by k.

The standard deviation is divided by k.

The standard deviation is multiplied by -k.

The standard deviation is unchanged.

33 Round eachz-score to the nearest hundredth. A data set has a mean of x=4050 and a standard deviation of119. Find thez-score for each of the following.

(a) x= 3840 (b) x= 4200 (c) x= 4300 (d) x= 4030