Math Exam I
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 ___. A) 0, 0.67 B) 0.8, 0.93 C) -0.67, 0 D) 0, 2 E) None of these is correct.
A) 0, 0.67
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. A) $4440.50 Bl $5678.56 C) $4070.00 D) $5110.70 E) None of these is correct.
A) 4440.50
Determine whether the elevated 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. A) Population B) Sample
A) Population
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? A) Yes B) No C) Sometimes, but not always, the distributions are the same.
A) Yes
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. A) $84.04 B) $67.96 C) $79 D) $64 E) $70
B) $67.96
Obtain the population standard deviations 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 48 67 68 43 73 41 93 A) 16.5 B) 15.6 C) 272.7 D) 243.3
B) 15.6
Solve the problem. A survey of patients at a hospital classified the patients by gender and blood type, as seen in the table. B Type Male Female A 105 93 B 95 68 O 168 148 AB 15 18 What percent of the female patients have type-O blood? Round your answer to the nearest tenth of a percent. A) 27.1% B) 43.1% C) 24.8% D) 24.5% E) 43.9%
B) 43.1%
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. A) Class B) Class 2 C) The classes have the same median.
B) Class 2
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? A) An interest in astrology that made the student curious about whether birth month is related to GPA. B) GPA, month of birth C) All enrolling students at the small college D) 892 college students E) The year 2001
B) 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. Activity Percent 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? A) Yes B) No C) There is not enough information to answer the question.
B) No
Classify the variables as categorical or quantative. The number of people on a jury. A) Categorical B) Quantative
B) Quantitative
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. A) Z=X-3.6/31.8 B) Z=X-31.8/3.6 C) Z=-31.8/3.6 D) X=Z-31.8/3.6
B) Z=X-31.8/3.6
Find the mode for the given sample data. 20, 32, 46, 32, 49, 32, 49 A) 37.1 B) 32 C) 49 D) 46
B)32
Find the deviation for a sample of data. Here are the prices for 8 randomly selected CD players: $422 $407 $384 $236 $265 $210 $375 $166 A) $215.5 B) $265 C) $99.9 D) $759,528.1 E) $829,391.0
C) $99.9
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. HW time # of Students 0-14 2 15-19 4 30-44 10 45-59 16 60-74 6 75-89 2 A) 10% B) 0.10 C) 0.25 D) 10 E) None of these is correct.
C) 0.25
In a standard Normal model, state what value(s) of z cuts off the described region. the lowest 96% A) 1.03 B) -1.38 C) 1.75 D) 1.82 E) -1.75
C) 1.75
Solve the problem. The test scores of 19 students are listed below. Find the interquartile range (IQR). 91 46 86 71 58 64 97 55 90 76 82 83 52 88 72 43 92 94 65 A) 32.5 B) 28 C) 32 D) 31.5 E) 25
C) 32
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? A) 59.87% B) 47.15% C) 40.13% D) 9.87% E) 38.21%
C) 40.13%
Describe the expected distribution: Heights of a group of male professional athletes, half of whom are gymnasts and half of whom are basketball players. A) The distribution would probably be normal B) The distribution would probably be unimodal C) The distribution would probably be bimodal. D) The distribution would probably be triangular E) The distribution would probably be uniform.
C) The distribution would probably be bimodal.
Would you expect a distribution of the variable to be? The heights of adult females attending a concert. A) The distribution would probably be skewed to the left. B) The distribution would probably be geometric. C) The distribution would probably be symmetric. D) The distribution would probably be uniform. E) The distribution would probably be skewed to the right.
C) The distribution would probably be symmetric.
Provide an appropriate response. Which of the variables below do you think will be roughly normally distributed? a. Weights of 40 year old males b. Incomes of 40 year old adults c. The numbers that show up when you roll a balanced die once d. The amount of coffee which a filling machine puts into "4 ounce jars" A) a, b, d B) a only C) d only D) a, b, c, d
C) d only
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 24 24 24 25 25 26 26 27 28 28 30 32 33 40 42 A) 15 22.5 25 29 42 B) 15 18 22.5 25 29 40 42 C) 15 22.5 25 29 40 42 D) 15 22.5 25 29 33 40 42 E) None of these is correct
D) 15 22.5 25 29 33 40 42
Identify outlier, If there are any, in the given data. The test scores of 15 students are listed below. 37 55 48 65 67 69 71 73 74 77 80 82 87 90 99 A) 37, 48, & 99 B) 99 C) 37, 99 D) 37 E) None of these are correct
D) 37
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. A) $641.63 B) $501.30 C) $513.30 D) $427.75 E) $320.75
D) 427.75
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? A) 5.00% B) 6.68% C) 42.37% D) 43.85% E) 93.32%
D) 43.85%
Find the percent of a standard Normal model found in the given region. z < 1.13 A) 88.09% B) 89.07% C) 12.92% D) 87.08% E) 84.85%
D) 87.08%
Solve the problem. The test scores of 15 students are listed below. Find the lower quartile (Q1). 42 45 50 57 60 63 66 70 73 78 85 87 90 94 95 A) 85 B) 60 C) 58.5 D) 86 E) 57
E) 57
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 69 71 71 73 73 74 76 77 77 78 79 80 81 81 82 83 85 89 92 93 94 97 98 A) 25 57 72 81 98 B) 25 57 72 81 98 C) 25 58 72 81 98 D) 25 58 72 81 98 E) None of these is correct
E) None of these is correct.
