CHAPTER 3 STATS

Following are the closing prices (in dollars) of a certain stock for the past 20 trading days. Find the population standard deviation for the closing prices.

$11.10

A data set has a mean of 177 and a standard deviation of 20. Compute the coefficient of variation.

0.11

According to Chebyshev's theorem, the maximum proportion of data values from a data set that are more than 1.5 standard deviations from the mean is .

0.44

Given that the variance for a data set is 1.20 , what is the standard deviation?

1.10

Find the mode for the following data set:10 30 10 36 26 22

10

Find the range of the set of values 4, 13, 3, 10, and 5.

10

Find the mode for the following data set:33 28 22 11 11 17

11

What is the midrange of the following data set?5, 11, 10, 12, 4, 12, 18, 18, 18

11

What is the range of the set of values 5, 8, 3, 9, and 17.

14

The grades for the trigonometry exam are listed below. Find the range. 85, 76, 93, 82, 84, 90, 75

18

The average weight of adult male bison in a particular federal wildlife preserve is 1450 pounds with a standard deviation of 240 pounds. Find the weight of an adult bull whose is z-score 1.5.

1810 lb

For the data set below, find the upper outlier boundary. 154, 160, 146, 146, 131, 148, 164, 199, 169, 139, 165

193.5

Use the given frequency distribution to approximate the mean. Class: 0-9, 10-19, 20-29, 30-39, 40-49. Freq: 18,18, 9,9,9

20.7

Find the median for the following data set:27 21 15 25 15

21

Find the mean for the following data set:28 25 23 34 14 14

23

Find the mean for the following data set:32 15 29 15 25

23.2

The number of police officers in selected city districts is listed below. Find the mode. 24,26,24,30,23,28,19,31,24,26, 19

24

Find the median of the data in the following stem-and-leaf plot. The leaf represents the ones digit.

26

The following table presents the heights (in inches) of a sample of college basketball players. Height: 68-71, 72-75, 76-79, 80-83, 84-87 Freq: 3,5,2,2,2

28.8

A recent survey of a new diet cola reported the following percentages of people who liked the taste. Find the weighted mean of the percentages. Area: 1,2,3 %favored: 30, 25,50 Number surveyed: 2500, 1500,3000

38

Find the sample variance for the following data set: 25 20 19 15 31

38

Find the sample variance for the following data set:25 20 19 15 31

38

Find the mode for the following data?5, 4, 3, 4, 5, 6, 5, 5, 3, 4

5

Approximate the population variance given the following frequency distribution. Class: 0-19,20-39,40-59, 60-79,80-89 Freq: 15,13,8,10,10

857.0

Which of the following is the properly rounded mean for the given data?7, 8, 13, 9, 10, 11

9.7

The completion times for a certain marathon race was 3 hours with a standard deviation of 0.5 hours. What can you determine about these data by using Chebyshev's Inequality with K=2

At least 75% of the completion times are between 2 hours and 4 hours.

The average resident of Metro City produces 570 pounds of solid waste each year, and the standard deviation is approximately 70 pounds. Use Chebyshev's theorem to find the weight range that contains at least of 75% all residents' annual garbage weights.

Between 430 and 710 pounds

Which of the following is true?

D5 = P50 = Q2

If a distribution is negatively skewed as shown in the figure below, the mean will fall to the right of the median and the mode will fall to the left of the median.

False

The interquartile range IQR is found by subtracting the mean from the maximum value of a data set.

False

Gina and Stewart are surf-fishing on the Atlantic coast, where both bluefish and pompano are common catches. The mean length of a bluefish is 288 millimeters with a standard deviation of 63mm. For pompano, the mean is 128mm with a standard deviation of 31. Stewart caught a bluefish that was long 307mm, and Gina caught a pompano that was 189mm long. Who caught the longer fish, relative to fish of the same species?

Gina

A soft-drink bottling company fills and ships soda in plastic bottles with a target volume of 354 milliliters. The filling machinery does not deliver a perfectly consistent volume of liquid to each bottle, and the three quartiles for the fill volume are Q1 = 352, Q2 = 356, and Q3 = 359.A fill volume of 344 mL is considered low. Would a fill volume of 344 mL be considered an outlier?

No

A data set contains three unique values. Which of the following must be true?

None of these

For the data shown in the histogram, which of the following choices best describes the relationship between the median and the mean?

median ≈ mean

A characteristic or measure obtained by using all the data values for a specific population is called a .

parameter

For a set of data with a mean of 6 and a variance of 9, approximately 68% of the values will fall between 3 to 9.

true

Given the following boxplot where m is the median value, what statement could be made about the distribution of the data?

The distribution is approximately symmetric.

Assuming the population is bell-shaped, approximately what percentage of the population values are between 39 and 63?

almost all (greater than 95%)

The size of the box in a boxplot shows the ________ of the data set.

interquartile range

What is the median of the following set of values?2, 16, 14, 10, 14, 9, 10, 14

12

For the data set below, list the outliers, if any. 45 50 47 70 47 12 41 43 64 53 31 63 37 45 66 63 53 60 93 59

12 and 93

A data set has a median of 84, and six of the numbers in the data set are less than median. The data set contains a total of n numbers.If n is odd, and exactly one number in the data set is equal to 84, what is the value of n?

13

A random sample of weights of sapphires in a jeweler's collection is shown. Find the mean of the sample.

5.69

The following population parameters were obtained from a graphing calculator. Assuming the population is bell-shaped, between what two values will approximately 68% of the population be?

52 to 74

For the data set below, find the first quartile. 78 65 63 67 67 64 72 78 75 65 74

65

A paint manufacturer discovers that the mean volume of paint in a gallon-sized pail is 1 gallon with a standard deviation of 0.05 gallons. The paint volumes are approximately bell-shaped. Estimate the percent of pails with volumes between 0.95 gallons and 1.05 gallons.

68%

Identify the five number summary of the following data set. 7,11,21,28,32,33,37,43

7, 16, 30, 35, 43

A soft-drink bottling company fills and ships soda in plastic bottles with a target volume of 354 milliliters. The filling machinery does not deliver a perfectly consistent volume of liquid to each bottle, and the three quartiles for the fill volume are Q1= 354, Q2= 358 and Q3-362

8

Following are heights, in inches, for a sample of college basketball players. 8377838484817983837777827880838381848181 Find the mean height of the basketball players.

81.2 inches

Approximate the sample variance given the following frequency distribution. Class: 0-19,20-39,40-59,60,79,80-99. Freq: 14,15,9,9,9

810.4

A student has an average of 78 on seven chapter tests. If the student's scores on six of the tests are 72, 82, 84, 66, 68, and 89, what was the score on the remaining test?

85