Math Unit 1 Exam Questions

Find the range: The manager of an electrical supply store measured the diameters of the rolls of wire in the inventory. The diameters of the rolls (in meters) are listed below 0.229 0.119 0.465 0.406 0.596 0.29

0.4777

Find the mean: The local exotic pet dealers earned these commissions last month: $3687.64 $4955.22 $3402.76 $1345.86 $4232.73 $1091.72 $4465.90 $2238.21 $3777.03 $4128.94

$3332.60

Create a stem plot: The ages of the 45 members of a track and field team are listed below: Construct a split-stemplot. 21 18 42 35 32 21 44 25 38 48 14 19 23 22 28 32 34 27 31 17 16 41 37 22 24 33 32 21 26 30 22 27 32 30 20 18 17 21 15 26 36 31 40 16 25

1/4 1/5 6 6 7 7 8 8 9 2/0 1 1 1 1 2 2 2 3 4 2/5 5 6 6 7 7 8 3/0 0 1 1 2 2 2 2 3 4 3/5 6 7 8 4/ 0 1 2 4 4/8

A student earned grades of C, A, B, and A. Those courses had the corresponding number of credit hours: 4, 5, 1, and 5. The grading system assigns quality points to letter grades as follows: A=4, B=3, C=2, D=1, and F=0. Compute the grade point average (GPA) and round the result.

3.40

Find the median: the normal monthly precipitation (in inches) for September is listed for 20 different European cities. 3.5 1.6 2.4 3.7 4.3 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

3.45 in

The frequency distribution below summarizes the home sale prices in the city of Auburn for the month of September. Determine the width of each class. (Sales price in thousand $) Frequency 80.0-110.9 2 111.0-141.9 5 142.0-172.9 7 173.0-203.9 10 204.0-234.9 3 235.0-265.9 1

31

Find the standard deviation: list below are the amounts of time (in months) that the employees of a store have been working at the store 2 3 6 15 29 36 64 87 101 122

44.1 monthers

The test scores of 32 students are listed below. Find P46 32 37 41 44 46 48 53 55 56 57 59 63 65 66 68 69 70 71 74 74 75 77 78 79 80 82 83 86 89 92 95 99

68

Find the mean: The heights of a group of professional badminton players are summarized in the frequency distribution below. Height (in) Frequency 70-71 1 72-73 4 74-75 9 76-77 11 78-79 9 80-81 4 82-83 3

76.8 in

The customer service department of a phone company is experimenting with two different systems. On Monday they try the first system which is based on an automated menu system. On Tuesday they try the second system in which each caller is immediately connected with a live agent. A quality control manager selects a sample of seven calls each day. He records the time for each customer to have his or her question answered. The times (in minutes) are listed below. Automated Menu: 11.8 7.5 4.0 2.9 9.2 6.3 5.5 Live Agent: 6.5 2.5 4.5 4.1 3.4 5.2 3.7

Automated Menu: 45.4%, Live agent: 30.4%

Which of the following statements regarding percentiles is true? (more than one statement may be true) A: In any data set, P90 is greater than P80 B: In any data set, P10+P90/2 is equal to Q2 C: In a set o 20 test scores, the percentile of the second highest score is 95

Only A

Determine the level of measurement: The sample of mattresses categorized from softest to firmest

Ordinal

The scores on a recent statistics test are given in the frequency distribution below. Construct the corresponding relative frequency distribution. Found relative frequencies to the nearest hundredth of a percent if necessary Scores Frequency 0-60 5 61-70 11 71-80 12 81-90 7 91-100 1

Scores Relative Frequency 0-60 13,89% 61-70 30.56% 71-80 33.33% 81-90 19.44% 91-100 2.78%

A post office employs 100 rural carriers and 100 city carriers. The personnel manager randomly selects 20 of the rural carriers and 20 of the city carriers and questions them about recent encounters with dogs. Does this sampling plan result in a random sample? Simple Random sample? Explain.

Yes; no. The sample is random because all employees have the same chance of being selected. It is not simple random sample because some samples are not possible, such as a sample consisting of 30 rural carriers and 10 city carriers

If the standard deviation of a set of data is zero, what can you conclude about the set of values?

all values are identical

Observation or experiment: A hospital gives medication to a group of ten patients and a placebo to another group of ten patients to find out if the medication has an effect on the patients' illness

experiment

Determine the level of measurement: Temperatures of an active volcano at various depths

interval

Find the mode: Listed below are the heights (in inches) of each snowfall in Auburn last year. 9 15 24 13 16 101 87 10 14 17 102

no mode

Which type of sampling: 51, 36, and 47 students are selected from the Freshman, Sophomore, and Junior classes with 513, 362, and 471 students respectively

stratified

Which type of sampling: a sample consists of every 37th employee from a group of 581 employees

systematic

The heights of the adults in one town have a mean of 66.9 inches and a standard deviation of 3.4 inches. What can you conclude from Chebyshev's theorem about the percentage of adults in the town whose heights are between 56.7 and 77.1 inches?

the percentage is at least 88.9%