Unit 1 assignment

Fifty part-time students (taking three courses or less) were asked how many courses they were taking this term. The (incomplete) results are shown below: 1 course, frequency 30, relative frequency 0.6 2 courses, frequency 15 3 courses... What is the cumulative frequency for students taking 1 or 2 courses?

.9

How does sleep deprivation affect your ability to drive? A recent study measured the effects on 19 professional drivers. Each driver participated in two experimental sessions: one after normal sleep and one after 27 hours of total sleep deprivation. The treatments were assigned in random order. In each session, performance was measured on a variety of tasks including a driving simulation. In the experiment, researchers evaluating subject's performance must not know which treatment is being applied at the time. Such a design is referred to as _________.

blinding

Ms. Smith wants to find out why students take introductory statistics at the University of Utah this semester. She finds out that there are 20 introductory statistics classes offered this semester at the U. with a total of 4,000 students enrolled. She wants to select 100 students for her sample. Suppose she randomly picks 5 introductory classes out of the 20, and then randomly picks 20 students out of each of these 5 classes. What method of sampling is she using?

cluster

"Percent of body fat" is an example of _________ data.

continuous

Ms. Smith wants to find out why students take introductory statistics at the University of Utah this semester. She finds out that there are 20 introductory statistics classes offered this semester at the U. with a total of 4,000 students enrolled. She wants to select 100 students for her sample. Suppose she herself is enrolled in FCS3210 so she randomly picks 100 students from FCS3210 for her sample. What method of sampling is she using?

convenience

"Marital status" is an example of _________ data.

discrete

Ski resorts are interested in the mean age that children take their first ski and snowboard lessons. They need this information to plan their ski classes optimally. "Number of children" is an example of ________ data.

discrete

A survey asks a group of investment advisors to indicate the average return on investment they obtain for their customers. Here are some of their answers: -50%, -18%, 0%, 2%, 50%, 300%.

interval

A survey asks you to identify your race/ethnicity using the following questions: ________ White ________ African American ________ Latino ________ Asian ________ Native American or American Indian ________ Other

nominal

A survey poses the following question: "Are you a smoker? Possible answers are either yes or no. What level of measurement is the resulting data?

nominal

A survey poses this question about your friendship circle: ________ I have many close friends ________ I have a few close friends ________ I have one close friend ________ I don't have any close friends

ordinal

How does sleep deprivation affect your ability to drive? A recent study measured the effects on 19 professional drivers. Each driver participated in two experimental sessions: one after normal sleep and one after 27 hours of total sleep deprivation. The treatments were assigned in random order. In each session, performance was measured on a variety of tasks including a driving simulation. In the experiment, treatments were assigned in random order, which eliminated the effect of any "learning" that may take place during the first experimental session. Such a design is referred to as _________________.

random assignment

A survey poses the following question: "If you are a smoker, how many cigarettes did you have today?" What level of measurement are the resulting data?

ratio

Ms. Smith wants to find out why students take introductory statistics at the University of Utah this semester. She finds out that there are 20 introductory statistics classes offered this semester at the U. with a total of 4,000 students enrolled. She wants to select 100 students for her sample. Suppose she obtains the list of these 4,000 students, assign a number of 1-4,000 to each of them, and use a computer program to randomly select 100 numbers between 1-4,000. What sampling method is she using?

simple random

Ms. Smith wants to find out why students take introductory statistics at the University of Utah this semester. She finds out that there are 20 introductory statistics classes offered this semester at the U. with a total of 4,000 students enrolled. She wants to select 100 students for her sample. Suppose she divides students into four groups: freshman, sophomore, junior, and senior, and then randomly select 25 from each group to be in her sample. What method of sampling is she using?

stratified

Ski resorts are interested in the mean age that children take their first ski and snowboard lessons. They need this information to plan their ski classes optimally. Which of the following is a statistic of interest in this study?

the sample mean age of children who take their first snowboard lesson

Ski resorts are interested in the mean age that children take their first ski and snowboard lessons. They need this information to plan their ski classes optimally. Which of the following describes data for this study?

values for X, such as 3, 7, and so on

Fifty part-time students (taking three courses or less) were asked how many courses they were taking this term. The (incomplete) results are shown below: 1 course, frequency 30, relative frequency 0.6 2 courses, frequency 15 3 courses... What is the cumulative frequency for students taking 1, 2, or 3 courses?

1.0

Fifty part-time students (taking three courses or less) were asked how many courses they were taking this term. The (incomplete) results are shown below: 1 course, frequency 30, relative frequency 0.6 2 courses, frequency 15 3 courses... What is the relative frequency for students taking 2 courses?

15/50 or 0.3

Here are some data: -1, 3, 0, 3, 5, -3, 2, 0, 4, 1, 6, 5, 6, 7, 3. What is the mean?

2.73

Fifty part-time students (taking three courses or less) were asked how many courses they were taking this term. The (incomplete) results are shown below: 1 course, frequency 30, relative frequency 0.6 2 courses, frequency 15 3 courses... What is the cumulative frequency for students taking exactly 2 courses?

30%

Fifty part-time students (taking three courses or less) were asked how many courses they were taking this term. The (incomplete) results are shown below: 1 course, frequency 30, relative frequency 0.6 2 courses, frequency 15 3 courses... How many students are taking 3 courses?

5

Fifty part-time students (taking three courses or less) were asked how many courses they were taking this term. The (incomplete) results are shown below: 1 course, frequency 30, relative frequency 0.6 2 courses, frequency 15 3 courses... What is the relative frequency for students taking 3 courses?

5/50 or .1

Fifty part-time students (taking three courses or less) were asked how many courses they were taking this term. The (incomplete) results are shown below: 1 course, frequency 30, relative frequency 0.6 2 courses, frequency 15 3 courses... What percent of students take 1 or 2 courses?

90%

Ski resorts are interested in the mean age that children take their first ski and snowboard lessons. They need this information to plan their ski classes optimally. Which of the following is a variable in this study?

X = the age of one child who takes his or her first ski or snowboard lesson

Ski resorts are interested in the mean age that children take their first ski and snowboard lessons. They need this information to plan their ski classes optimally. What is the sample of this study?

a group of these children

How does sleep deprivation affect your ability to drive? A recent study measured the effects on 19 professional drivers. Each driver participated in two experimental sessions: one after normal sleep and one after 27 hours of total sleep deprivation. The treatments were assigned in random order. In each session, performance was measured on a variety of tasks including a driving simulation. "Performance measured in assigned tasks" is ___________.

a response/dependent variable

Ski resorts are interested in the mean age that children take their first ski and snowboard lessons. They need this information to plan their ski classes optimally. Which of the following is the population of the study?

all children who take ski or snowboard lessons

How does sleep deprivation affect your ability to drive? A recent study measured the effects on 19 professional drivers. Each driver participated in two experimental sessions: one after normal sleep and one after 27 hours of total sleep deprivation. The treatments were assigned in random order. In each session, performance was measured on a variety of tasks including a driving simulation. "Amount of sleep" is ________.

an explanatory/independent variable