MATH 225n Week 4 Midterm Exam Week 1 - 4

QUESTION: 1 In a study about political preferences, a researcher randomly selected an equal number of men and women to survey. Answer: Is the study observational or experimental? If it is an experiment, what is the controlled factor? Answer: The study is an observational study. QUESTION: 2 A survey was given where students in a class were asked to state their eye color. What is the level of measurement of the data? Answer: Nominal QUESTION: 3 Matthew wants to estimate the mean height of clients attending his store. He records the heights of 100 randomly selected clients attending the store. What is the population? Answer: all the clients attending the store QUESTION: 4 To study the eating habits of all athletes in his school, Christopher obtains a list of the athletes, divides the list into 5 groups, and collects data from several of these groups. Which type of sampling is used? Answer: Stratified sampling QUESTION: 5 In order to study the mean blood pressure of people in his town, Richard samples the population by dividing the residents by age and randomly selecting a proportionate number of residents from each age group. Which type of sampling is used? Answer: Stratified sampling QUESTION: 6 A small startup company wishes to know how many hours, per week, that its employees spend commuting to and from work. The number of hours for each employee are shown below. Construct a frequency table for grouped data using four classes. 17, 2, 19, 14, 13, 21, 21, 9, 17, 10, 3, 12, 15, 10, 15, 8, 5, 21, 17, 13 Answer: 971428182979 QUESTION: 7 The frequency table below shows the ages of the students in an astronomy class. 962025837719Complete the Relative Frequency column of the table. Enter Answer as an simplified fraction. Answer: QUESTION: 8 A group of students were surveyed about the number of times they went to a movie theater last year. Their responses are summarized in the relative frequency table below. What is the missing relative frequency? Number of Movies Relative Frequency 0−1 0.08 2−3 0.20 4−5 0.30 6−7 □ 8−9 0.10 10 or more 0.08 ANSWER: 0.24 QUESTION: 9 The values and relative frequencies for a set of data are shown below. Complete the cumulative relative frequency table. Answer: 1038312304838 QUESTION: 10 A data set is summarized in the frequency table below. Using the table, determine the number of values less than or equal to 7. Value Frequency 905510163182 23 905510163529 34 905510163209 46 905510163209 53 905510163209 62 905510163209 73 905510163209 84 905510163209 95 905510163209 104 905510163209 114 905510163209 122 905510163209 Answers: 21 QUESTION: 11 Describe the shape of the given histogram. 1238050178091 Answer: unimodal and left-skewed QUESTION: 12 A set of data is summarized by the stem and leaf plot below. 2251710-5824421 1 The value 24 appearstime(s) in the data set. The 1976754-5817472 2 value 31 appearstime(s) in the data set. The 1976754-5823221 1 value 49 appearstime(s) in the data set. The 1976754-5251083 3 value 52 appears QUESTION: 13 Find the median