7. statistics, data analysis, and interpretation

A. 20 questions

question 10: In a certain test there are 100 multiple choice questions, each with 5 answer choices, out of which only 1 is correct. If a student answers all questions randomly, how many questions, on average, can he expect to get right? A. 20 questions B. 23 questions C. 25 questions D. 33 questions E. 50 questions

B. 50%

question 11: What percent of students spent less than 28 minutes reading yesterday? A. 25% B. 50% C. 75% D. 90% E. 100%

C. 48

question 12: The mean age of a group of 12 dentists is 28 years old. When 3 dentists join the group, the mean age increases by 4 years. What is the mean age of the new dentists? A. 44 B. 46 C. 48 D. 50 E. 52

B. 8,200

question 13: If the number of students who passed the examination in 2017 was 5,412; what was the total number of students who took the examination in 2017? A. 6,600 B. 8,200 C. 8,500 D. 9,400 E. 10,200

B. Jeremy's score with Class B has the largest z-score.

question 14: Jeremy received a score of 76. Using the information in the table below, with which class does Jeremy have the largest z-score? A. Jeremy's score with Class A has the largest z-score. B. Jeremy's score with Class B has the largest z-score. C. Jeremy's score with Class C has the largest z-score. D. Jeremy's score with both Class A and Class C has the largest z-score. E. Jeremy's score has the same z-score for all three classes.

E. mode < median < mean

question 15: Soo received 82, 84, 88, 82, 90, and 96 on her first six anatomy tests. What is the relationship between the mean, median, and mode? A. mean < median < mode B. mean < mode < median C. median < mean < mode D. mode < mean < median E. mode < median < mean

D. 40%

question 16: What is the approximate percent decrease in the exports from 2014 to 2015? A. 25% B. 30% C. 35% D. 40% E. 45%

B. Dentist B has a z-score of the smallest magnitude.

question 17: Three dentists work in the same dental clinic. The mean of the number of extracted teeth in this clinic is 12. Dentist A extracted 10 teeth, Dentist B extracted 13 teeth, and Dentist C extracted 9 teeth. Which of the following is true? A. Dentist A has a z-score of the smallest magnitude. B. Dentist B has a z-score of the smallest magnitude. C. Dentist C has a z-score of the smallest magnitude. D. Dentist A has a z-score of the largest magnitude. E. Dentist B has a z-score of the largest magnitude.

D. 80%

question 18: In 2013, the value of imports was approximately what percent of the value of exports? A. 65% B. 70% C. 75% D. 80% E. 85%

A. 16%

question 19: The length of symptoms of the flu is normally distributed with an average of 7 days and a standard deviation of 2 days. What is the probability that someone with the flu will have symptoms for less than 5 days? A. 16% B. 34% C. 50% D. 84% E. 95%

D. mean = 8, median = 5, mode = 5

question 1: Find the mean, median, and mode for the following data set: {3, 3, 4, 5, 5, 5, 19, 20} A. mean = 7, median = 5, mode = 2 B. mean = 7, median = 5, mode = 5 C. mean = 7, median = 5.5, mode = 6 D. mean = 8, median = 5, mode = 5 E. mean = 8, median = 6, mode = 5

D. 62%

question 20: What percentage of the total number of students chose the top 2 flavors? A. 31% B. 42% C. 54% D. 62% E. 70%

D. 16.5, 15, 13

question 21: Find the mean, median, and mode of the following data set: {2, 24, 13, 17, 30, 13} A. 13, 15, 16.5 B. 13, 17, 13 C. 15, 13, 16.5 D. 16.5, 15, 13 E. 17, 16.5, 13

B. 67

question 22: How many students had less than 700 words in their essays? A. 60 B. 67 C. 72 D. 78 E. 82

D. 15

question 23: What is the range of the data in the box plot shown above? A. 7 B. 10 C. 14 D. 15 E. 19

B. 3.25

question 24: Melissa's grades this semester are as follows: Anatomy (5 credits): A Cell Biology (3 credits): B Sociology (2 credits): B Medical Terminology (2 credits): C If an A is assigned 4 grade points, a B is 3 grade points, and a C is 2 grade points, what is Melissa's grade point average this semester? A. 3.20 B. 3.25 C. 3.30 D. 3.35 E. 3.40

D. 189

question 25: The mean score of a set of tests is 160 and the standard deviation is 14. The teacher decides that a score that is between 2 and 2.5 standard deviations above the mean will receive a grade of "A-". Which of the following test scores would earn an "A-"? A. 177 B. 178 C. 184 D. 189 E. 196

B. Tuesday

question 26: Which day corresponds to the highest wage for Sam? A. Monday B. Tuesday C. Thursday D. Friday E. Sunday

A. 80%

question 27: A section of 25 students has an average test grade of 82%. Three new students were admitted to the section and they received scores of 55%, 62%, and 73%. What is the new average of the class after these three students joined the section? A. 80% B. 81% C. 82% D. 83% E. 84%

A. 25%

question 28: What percent of country clubs in Essex County have more than 120 members? A. 25% B. 50% C. 75% D. 90% E. 100%

C. 4

question 29: A sample data set has 9 entries, shown below. What is the mode? {5, 3, 5, 4, 6, 6, 4, 3, 4} A. 3 B. 3.78 C. 4 D. 5 E. 6

E. 84

question 2: A group of people have been asked their favorite genre of movies. If 25% of the total number of people chose Sci-Fi as their favorite genre, then how many people have been surveyed in total? A. 80 B. 81 C. 82 D. 83 E. 84

C. 1997

question 30: In which year was the difference between the exports from Companies A and C the minimum? A. 1995 B. 1996 C. 1997 D. 1999 E. 2001

B. 157 cm

question 31: The average height of four people is 172 cm. When a fifth person joins, the average height of the five people together becomes 169 cm. What is the height of the fifth person? A. 155 cm B. 157 cm C. 159 cm D. 161 cm E. 163 cm

C. $1,340

question 32: A coffee shop has 7 baristas. It pays monthly salaries of $1,200 to each of 3 baristas, $1,300 to each of 2 baristas, and $1,600 to each of the remaining two baristas. Which of the following is closest to the average monthly salary of these baristas? A. $1,250 B. $1,300 C. $1,340 D. $1,420 E. $1,490

D. 23

question 33: The average of six numbers is 16. If the average of three of these numbers is 9, what is the average of the remaining three numbers? A. 13 B. 17 C. 21 D. 23 E. 27

D. 21

question 34: Based on the data set {15, 18, 21, 17, 19, 15}, what is the value that corresponds to the blue arrow indicated in the figure above? A. 15 B. 17 C. 19 D. 21 E. 23

B. 16 students

question 35: One hundred students take a test. The test score results for the student are normally distributed. 68 of the students score within one standard deviation of the mean, but none of the students has a score that equals the mean. How many students should we expect to have a score that is more than one standard deviation above the mean? A. 12 students B. 16 students C. 22 students D. 30 students E. 32 students

C. 40%

question 36: What is the percent increase in temperature from Thursday to Saturday? A. 30% B. 35% C. 40% D. 45% E. 50%

A. Student A

question 37: Three students take the same test and the mean of the test is 80 points. Student A scores 65 points, Student B scores 92 points, and Student C scores 68 points. Which student has a z-score of the largest magnitude? A. Student A B. Student B C. Student C D. Student B and Student C tie E. They all have the same z-score

B. $120 million

question 38: What is the dollar amount of profit at JS Corporation in 2017? A. $80 million B. $120 million C. $140 million D. $260 million E. $400 million

E. 2019

question 39: In which year was the difference between the number of participants from Chicago and Boston Marathons the least? A. 2014 B. 2015 C. 2017 D. 2018 E. 2019

A. 5 students

question 3: 200 students take an exam. The score results for the students are normally distributed. 136 of the students score within one standard deviation of the mean, and 190 of the students score within two standard deviations of the mean. How many students should we expect to have a score that is more than two standard deviations above the mean? A. 5 students B. 10 students C. 32 students D. 54 students E. 64 students

C. 12

question 40: If the number of snow days in December represents 25% of the total number of days snowed in the four months represented in the graph above, then how many snow days did February have? A. 10 B. 11 C. 12 D. 13 E. 14

D. 13.5

question 41: The mean of a data set {11, 14, 13, x} is 15. What is the median of these four values? A. 9 B. 10.5 C. 12.5 D. 13.5 E. 15

D. 6,800

question 42: If the number of students who passed the examination in 2015 was 4,800, then what was the number of students who passed the examination in 2018, assuming the total number of students is constant? A. 5,000 B. 5,400 C. 5,800 D. 6,800 E. 7,200

C. 75%

question 43: What percent of students spent more than 29 minutes practicing the flute each day? A. 25% B. 50% C. 75% D. 85% E. 95%

C. 12

question 44: There are 15 girls and 10 boys in a class. The average age of girls is 14 years and the average age of boys is 9 years. What is the average age of the class? A. 10 B. 11 C. 12 D. 13 E. 14

C. 19

question 45: In February, the total number of individuals was 100. In April, it was 70. What is the difference in the number of people that rode a bus between February and April? A. 15 B. 18 C. 19 D. 24 E. 30

C. 83.25

question 46: There are two classes offered by the anatomy department with 20 students in each class. For an exam, the average score of Class B was lower than the average score of Class A by 3.5 points. If the average of both classes together is 85, what is the average of Class B? A. 76.25 B. 79.75 C. 83.25 D. 86.75 E. 90.25

B. 13%

question 47: What percent of the total number of children in five villages live in Infinite Village? A. 10% B. 13% C. 16% D. 19% E. 22%

B. The z-score is negative.

question 48: The mean of a data set is 132. What does this say about the z-score of a data point of 128? A. The z-score is zero. B. The z-score is negative. C. The z-score is positive. D. The z-score can be either zero or negative. E. The z-score can be either positive or negative.

D. 1/5

question 49: A university scheduled both engineering and biology graduations on the same day. Based on the information in the chart below, what proportion of engineering students are graduating with a master's degree? A. 1/2 B. 1/3 C. 1/4 D. 1/5 E. 1/6

C. Natasha's harvest with Town C has the smallest z-score.

question 4: Natasha harvested 32 kg of potato this season. Using the information in the table below, with which town does Natasha have the smallest z-score? A. Natasha's harvest with Town A has the smallest z-score. B. Natasha's harvest with Town B has the smallest z-score. C. Natasha's harvest with Town C has the smallest z-score. D. Natasha's harvest with both Town A and Town C has the smallest z-score. E. Natasha's harvest has the same z-score for all three towns.

B. -0.05

question 50: Which z-score is closest to the mean of a standardized normal distribution? A. -0.5 B. -0.05 C. 0.06 D. 0.3 E. 0.8

D. 1.5

question 51: A geography final exam's scores are normally distributed with a mean of 52 and a standard deviation of x. If x = 8, what is the z-score of a test grade of 64? A. -2.5 B. -1 C. 0.5 D. 1.5 E. 3

C. mean

question 52: The average of a large data set is 60. Which of the following must be greater than or equal to 60? A. mode B. median C. mean D. median and mean E. mode and mean

A. 2.5

question 53: If x is a random variable whose probability distribution function is given by a normal distribution with a mean of 7 and a standard deviation of 2, which of the following values of x is least likely? A. 2.5 B. 5 C. 7 D. 8 E. 11

A. median = 16, mode = 16

question 54: A group of friends recorded the number of hours they spent on their phones each week. They then organized the data in the following stem and leaf plot. Determine the median and mode of the data set. A. median = 16, mode = 16 B. median = 16, mode = 28 C. median = 17.5, mode = 16 D. median = 19, mode = 9 E. median = 21, mode = 28

D. 17

question 55: A bookstore owner kept track of the number of books sold per day for 15 days and created a stem-and-leaf plot to visualize the data. What is the average number of books sold per day at the bookstore? A. 9 B. 10 C. 14 D. 17 E. 19

B. 43

question 5: How many students have between 10 and 39 books? A. 33 B. 43 C. 53 D. 63 E. 73

E. The mean, median, and mode are the same.

question 6: All the values in a data set are the same. Which of the following is true? A. The mean is greater than the median. B. The median is greater than the mean. C. Only the mean and median are the same. D. Only the median and mode are the same. E. The mean, median, and mode are the same.

B. 22%

question 7: Car commuters represent what percentage of the total commuters in Fairfield County? A. 13% B. 22% C. 27% D. 32% E. 28%

C. 278,000

question 8: What is the difference between the productions of the two companies in 1996? A. 154,000 B. 181,000 C. 278,000 D. 352,000 E. 432,000

D. 88

question 9: Joanna's photo booth has 28 average visitors per day for the past 9 days. How many people must visit her booth on the 10th day to maintain a quota of 34 visitors per day? A. 22 B. 44 C. 66 D. 88 E. 110