Exam 3: Describing, Exploring, and Comparing Data

Find the indicated measure. -The test scores of 40 students are listed below. Find $\text { P85. }$ 30 35 43 44 47 48 54 55 56 57 59 62 63 65 66 68 69 69 71 72 72 73 74 76 77 77 78 79 80 81 81 82 83 85 89 92 93 94 97 98

The heights of the adults in one town have a mean of 67.1 inches and a standard deviation of 3.5 inches. What can you conclude from Chebyshev's theorem about the percentage of adults in the town whose heights are Between 60.1 and 74.1 inches?

Find the number of standard deviations from the mean. Round your answer to two decimal places. -The test scores on the Chapter 10 mathematics test have a mean of 52 and a standard deviation of 10. Andrea scored 86 on the test. How many standard deviations from the mean is that?

Solve the problem. -A student earned grades of 84, 78, 84, and 72 on her four regular tests. She earned a grade of 78 on the final exam and 86 on her class projects. Her combined homework grade was 87. The four regular tests count for 40% Of the final grade, the final exam counts for 30%, the project counts for 10%, and homework counts for 20%. What is her weighted mean grade? Round to one decimal place.

Construct a data set for which the range is misleading as a measure of variation. Explain why the range is misleading and suggest an alternative measure of variation.

A student earned grades of 84, 78, 84, and 72 on her four regular tests. She earned a grade of 78 on the final exam and 86 on her class projects. Her combined homework grade was 87. The four regular tests count for 40% Of the course grade, the final exam counts for 30%, the project counts for 10%, and homework counts for 20%. What is her weighted mean grade? Round to one decimal place.

Find the standard deviation of the data summarized in the given frequency distribution. -The manager of a bank recorded the amount of time each customer spent waiting in line during peak business hours one Monday. The frequency distribution below summarizes the results. Find the standard deviation. Round your answer to one decimal place. Waiting time Number of (minutes) customer 0-3 13 4-7 13 8-11 10 12-15 11 16-19 0 20-23 3

Find the variance for the given data. Round your answer to one more decimal place than the original data. -A class of sixth grade students kept accurate records on the amount of time they spent playing video games during a one-week period. The times (in hours) are listed below: 30.9 28.0 23.9 15.8 26.5 15.3 12.7 14.6 25.6 10.4

The number of hours per day a college student spends on homework has a mean of 6 hours and a standard deviation of 1.25 hours. Yesterday she spent 3 hours on homework. How many standard deviations from the Mean is that? Round your answer to two decimal places.

Solve the problem. -Jorge has his own business as a painter. The amounts he made in the last five months are shown below. \ 2426 \ 2463 \ 1451 \ 2154 \ 1119

Find the variance for the given data. Round your answer to one more decimal place than the original data. - 18 16 12 2 11

An online service ran a poll of its internet subscribers and asked whether they would re-elect the current President. Among the 1,304,240 responses, 768,731 answered "yes", 286,756 answered "no", and 248,753 said it was "too soon to decide". Given how large this sample is, can it be considered to be representative of the population of the United States? Explain.

Find the standard deviation of the data summarized in the given frequency distribution. -A company had 80 employees whose salaries are summarized in the frequency distribution below. Find the standard deviation. Salary (dollars) Employees 5,001-10,000 19 10,001-15,000 14 15,001-20,000 12 20,001-25,000 16 25,001-30,000 19

Find the standard deviation for the given sample data. Round your answer to one more decimal place than is present in the original data. -The top nine scores on the organic chemistry midterm are as follows. $47,55,71,41,82,57,25,66,81$

Solve the problem. -The amounts below represent the last twelve transactions made to Juan's checking account. Positive numbers represent deposits and negative numbers represent debits from his account. \ 28 -\ 20 \ 67 -\ 22 -\ 15 \ 17 -\ 38 \ 41 \ 53 -\ 13 \ 30 \ 75

The test scores of 40 students are listed below. Find P56. 30 35 43 44 47 48 54 55 56 57 59 62 63 65 66 68 69 69 71 72 72 73 74 76 77 77 78 79 80 81 81 82 83 85 89 92 93 94 97 98

Find the midrange for the given sample data. -The heights of a group of professional basketball players are summarized in the frequency distribution below. Find the mean height. Round your answer to one decimal place. Height (in.) Frequency 70-71 1 72-73 8 74-75 13 76-77 8 78-79 15 80-81 6 82-83 3

Find the median for the given sample data. -The normal monthly precipitation (in inches) for August is listed for 20 different U.S. cities. Find the median of the data. 3.5 1.6 2.4 3.7 4.1 3.9 1.0 3.6 4.2 3.4 3.7 2.2 1.5 4.2 3.4 2.7 0.4 3.7 2.0 3.6

Use the range rule of thumb to estimate the standard deviation. Round results to the nearest tenth. -A distribution of data has a maximum value of 83, a median value of 62.5, and a minimum of 42.

Which of the following is not a property of variance?