One use of a regression line is

a. to determine if any x-values are outliers.

b. to determine if any y-values are outliers.

c. to determine if a change in x causes a change in y.

d. to estimate the change in y for a one-unit change in x.

18. Past data has shown that the regression line relating the final exam score and the midterm

exam score for students who take statistics from a certain professor is:

final exam = 50 + 0.5 midterm

One interpretation of the slope is

a. a student who scored 0 on the midterm would be predicted to score 50 on the final exam.

b. a student who scored 0 on the final exam would be predicted to score 50 on the midterm

exam.

c. a student who scored 10 points higher than another student on the midterm would be

predicted to score 5 points higher than the other student on the final exam.

d. students only receive half as much credit (.5) for a correct answer on the final exam

compared to a correct answer on the midterm exam.

Questions 19 to 21: A survey asked people how often they exceed speed limits. The data are

then categorized into the following contingency table of counts showing the relationship between

age group and response.

Exceed Limit if Possible?

Age Always Not Always Total

Under 30 100 100 200

Over 30 40 160 200

Total 140 260 400

19. Among people with age over 30, what's the "risk" of always exceeding the speed limit?

a. 0.20

b. 0.40

c. 0.33

d. 0.50

20. Among people with age under 30 what are the odds that they always exceed the speed limit?

a. 1 to 2

b. 2 to 1

c. 1 to 1

d. 50%

21. What is the relative risk of always exceeding the speed limit for people under 30 compared to

people over 30?

a. 2.5

b. 0.4

c. 0.5

d. 30%

A polling agency conducted a survey of 100 doctors on the question "Are you willing to treat

women patients with the recently approved pill RU-486"? The conservative margin of error

associated with the 95% confidence interval for the percent who say 'yes' is

a. 50% b. 10% c. 5% d. 2%

11. Which one of these statistics is unaffected by outliers?

a. Mean

b. Interquartile range

c. Standard deviation

d. Range

12. A list of 5 pulse rates is: 70, 64, 80, 74, 92. What is the median for this list?

a. 74 b. 76 c. 77 d. 80

13. Which of the following would indicate that a dataset is not bell-shaped?

a. The range is equal to 5 standard deviations.

b. The range is larger than the interquartile range.

c. The mean is much smaller than the median.

d. There are no outliers.

14. A scatter plot of number of teachers and number of people with college degrees for cities in

California reveals a positive association. The most likely explanation for this positive

association is:

a. Teachers encourage people to get college degrees, so an increase in the number of

teachers is causing an increase in the number of people with college degrees.

b. Larger cities tend to have both more teachers and more people with college degrees, so

the association is explained by a third variable, the size of the city.

c. Teaching is a common profession for people with college degrees, so an increase in the

number of people with college degrees causes an increase in the number of teachers.

d. Cities with higher incomes tend to have more teachers and more people going to college,

so income is a confounding variable, making causation between number of teachers and

number of people with college degrees difficult to prove.

15. The value of a correlation is reported by a researcher to be r = 0.5. Which of the following

statements is correct?

a. The x-variable explains 25% of the variability in the y-variable.

b. The x-variable explains 25% of the variability in the y-variable.

c. The x-variable explains 50% of the variability in the y-variable.

d. The x-variable explains 50% of the variability in the y-variable.

16. What is the effect of an outlier on the value of a correlation coefficient?

a. An outlier will always decrease a correlation coefficient.

b. An outlier will always increase a correlation coefficient.

c. An outlier might either decrease or increase a correlation coefficient, depending on

where it is in relation to the other points.

d. An outlier will have no effect on a correlation coefficient.

September to December January to April . AVIA 100 - Introduction to Aviation . GEOG 102 - Global Environmental . GEOG 101 - Human Geographies: People, Systems: Process and Change Space and Change . ENVS 178 - Environmental Applications . GEOG 181 - Designing Effective Maps of Data Management and Statistics . CS 100 - Introduction to Computing . AVIA 101 - Professional Pilot Program Course . One of: . One elective . ENGL 109 - Introduction to Academic Writing o ENGL 129R - Written Academic English2. (No R required) This question is based on data about teacher salaries from the 50 states plus DC (so n = 51) in the mid 1980s. The variables are: c PAY, y: average annual public school teacher salary, in dollars. 0 SPEND, 2:1: Spending on public schools per student, in dollars. 0 AREA: Region (North, South, West). Table 1 below provides some summary statistics of the data: n Mean SPEND $3901 $3274 West 13 $26159 $3919 Table 1: Summary Statistics of Teacher Pay (a) Based only on Table 1, briey comment on the relationship between geographic area and mean teacher pay. (b) Based only on Table 1, briey comment on the relationship between mean public school expenditure (per student) and mean teacher pay. ((3) Briey explain why using a multiple linear regression model with teacher pay as the response variable with geographic area and public school expenditure (per student) can give further insight into the relationship(s) between these variables. Q6) The owner of an online sports store wants to compare the sales with the geographical distribu- tion of the population. According to Statistics Canada (2006 Census), 7.2% of the population lives in the Maritimes, 23.9% in Quebec, 38.6% in Ontario, 17.2% in the Prairies and 13.1% in British Columbia. Here is the breakdown in a random sample of orders. Maritimes Quebec Ontario Prairies British Columbia 22 105 185 66 36 At the 1% level of significance, is the distribution of destination of the orders shipped reflective of that of the population?The CDC publishes disease prevalence statistics for people of different ages, races, and geographic locations each year. In 2017, 50% of children in the US were classified as White, 14% were classified as Black, and 36% have an Other classification. Asthma prevalence varies by race - with a prevalence of 10% for White children, 18% for Black children, and 13% for Other children. a. What percent of Black children do not have asthma? b. What percent of US Children have asthma? c. What is the probability that a child that does not have asthma is White