Exam 1 stats

Find the mean of the data.The employees at Frank's Furniture earned the following amounts, in dollars, last week. $443.52 $441.04, $530.17, $471.67, $359.36%, $320.75 Round your answer to the nearest cent.

$427.75

Find the median for the given sample data.A new business had the following monthly net gains: $8519, $3555, $3325, $8084, $6496, $1738, $2369, $8140, $4070, $4811 Find the median net gain.

$4440.50

Find the specified percentile, quartile, or decile.The amount of Jen's monthly phone bill is normally distributed with a mean of $76 and a standard deviation of $12. Find the first quartile, Q1.

$67.96

Find the standard deviation for a sample of data.Here are the prices for 8 randomly selected CD players:$422 $407 $384 $236 $265 $210 $375 $166

$99.9

Fill in the blanks by standardizing the normally distributed variable.The amount of time that customers wait in line during peak hours at one bank is normally distributed with a mean of 15 minutes and a standard deviation of 3 minutes. The percentage of time that the waiting time lies between 15 and 17 minutes is equal to the area under the standard normal curve between ___ and ___.

0, 0.67

Provide the requested table entry.The data in the following table reflect the amount of time 40 students in a section of Statistics 101 spend on homework each day. Determine the value that should be entered in the Relative Frequency column for the class 30-44. 0-14: 2 15-29: 4 30-44: 10 45-59: 16 60-74:6 75-89: 2

0.25

In a standard Normal model, state what value(s) of z cuts off the described region.the lowest 96%

1.75

Construct a boxplot.The ages of the 21 members of a track and field team are listed below. Construct a boxplot for the data.15 18 18 19 22 23 2424 24 25 25 26 26 27 28 28 30 32 33 40 42

15 - 22.5- 25- 29 - 33 - 40x 42x

Obtain the population standard deviation, σ, for the given data. Assume that the data represent population data. Round your final answer to one more decimal place than that used for the observations.The test scores of 9 students are listed below.65 69 4867 68 4373 41 93

15.6

construct a boxplot.The test scores of 40 students are listed below. Construct a boxplot for the data set. 25 35 43 44 47 48 54 55 56 57 59 62 63 65 66 68 69 71 71 73 73 74 76 77 77 78 79 80 81 81 82 83 85 89 92 93 94 97 98

25 - 58 -----72 -- 81---98

Find the mode(s) for the given sample data.20, 32, 46, 32, 49, 32, 49

32

Solve the problem.The test scores of 19 students are listed below. Find the interquartile range (IQR).91 46 86 71 5864 97 55 90 7682 83 52 88 7243 92 94 65

32

Identify outliers, if there are any, in the given data.The test scores of 15 students are listed below.37 55 48 65 6769 71 73 74 7780 82 87 90 99

37

Solve the problem.The volumes of soda in quart soda bottles can be described by a Normal model with a mean of 32.3 oz and a standard deviation of 1.2 oz. What percentage of bottles can we expect to have a volume less than 32 oz?

40.13%

Solve the problem.A survey of patients at a hospital classified the patients by gender and blood type, as seen in the table. A: 105 (M) 93 (F) B: 95 (M) 84(F) O: 168 (M) 148 (F) AB: 15 (M) 18 (F) What percent of the female patients have type-O blood? Round your answer to the nearest tenth of a percent.

43.1%

Solve the problem. A bank's loan officer rates applicants for credit. The ratings can be described by a Normal model with a mean of 200 and a standard deviation of 50. If an applicant is randomly selected, what percentage can be expected to be between 200 and 275?

43.85%

Solve the problem.The test scores of 15 students are listed below. Find the lower quartile (Q1).42 45 50 57 6063 66 70 73 7885 87 90 94 95

57

Find the percent of a standard Normal model found in the given region.z < 1.13

87.08%

Two statistics classes (50 students each) took the same test. Shown below are histograms of the scores for the classes. Use the histograms to answer the question. Which class had the higher median score? class 1: unimodal, symmetrical class 2: bimodal, skewed to the left

Class 1

Select the best answer. A statistics student with an interest in astrology looked at the grade point averages of all 892 students that enrolled at a small college in Pennsylvania in 2001. She determined that GPA was not related to the month that students were born. What are the variables?

GPA, month of birth

Provide an appropriate response.A poll asked adults which activities they had engaged in during the past month. The results are listed below. dinner out: 55.7 sporting event: 15.1 movie: 45.6 Stroll: 5.1 Is it reasonable to conclude that 70.8% of those polled had seen a movie or gone to a sporting event during the past month?

No

Determine whether the evaluated group is a population or a sample.A researcher examines the records of all the registered voters in one city and finds that 43% are registered Democrats.

Population

Classify the variable as categorical or quantitative.The number of people on a jury

Quantitative

Would you expect a distribution of the variable to be? The heights of adult females attending a concert.

Symmetric

Describe the expected distribution: Heights of a group of male professional athletes, half of whom are gymnasts and half of whom are basketball players.

The distribution would probably be bimodal

Solve the problem.A meteorological office keeps records of the annual precipitation in different cities. For one city, the mean annual precipitation is 31.8 and the standard deviation of the annual precipitation amounts is 3.6. Let X represent the annual precipitation in that city. Determine the standardized version of X.

Z= (X-31.8)/3.6

Provide an appropriate response.For a given set of data, will the shapes of the frequency distribution and the relative frequency distribution be the same?

yes