60 Questions
| Total Attempts: 1089

Test1 sample for Stats221 class.

Questions and Answers

- 1.1. Consider the following bar chart of Baskepoints sources. Three of the following statements are correct, one is NOT. Which of the following statements is incorrect?
- A.
More points are scored in the 3-pt line than steals.

- B.
About 70% of the points come from Free throws and 2-point shots.

- C.
Most points come from the 2-point shots.

- D.
The distribution is skewed to the left.

- 2.Consider the following 5-number summary of 120 NBA teams scores: Which of the following observations in the data set would be called a suspected outlier?
- A.
An observation between 85 and 100.

- B.
An observation less than 125.

- C.
An observation between 70 to 100.

- D.
An observation greater than 145

- E.
E. There are no suspected outliers in this data set.

- 3.Here are the boxplots of Stats221 Final scores for Provo and Salt Lake Campus: T F Both distributions are skewed to the left.
- A.
True

- B.
False

- 4.Here are the boxplots of Stats221 Final scores for Provo and Salt Lake Campus: 1. T F Fifty percent of the SLC students scored approximately between 65 and 85.
- A.
True

- B.
False

- 5.Here are the boxplots of Stats221 Final scores for Provo and Salt Lake Campus: 1. T F Scores exhibit less spread for Provo than SLC.
- A.
True

- B.
False

- 6.Here are the boxplots of Stats221 Final scores for Provo and Salt Lake Campus: The interquartile range for SLC is about 20.
- A.
True

- B.
False

- 7.Here are the boxplots of Stats221 Final scores for Provo and Salt Lake Campus: The proportion of Provo scoring between 62 to 82 is greater than the proportion of SLC scoring between 65 to 85.
- A.
True

- B.
False

- 8.Here are the boxplots of Stats221 Final scores for Provo and Salt Lake Campus: The mean is greater than the median for scores in Provo.
- A.
True

- B.
False

- 9.Here are the boxplots of Stats221 Final scores for Provo and Salt Lake Campus: The proportion of SLC scoring below 85 is larger than the proportion of Provo scoring below 85.
- A.
True

- B.
False

- 10.Which of the following graphical displays can be drawn using only the 5 number summary?
- A.
Scatterplot

- B.
Bar graph

- C.
Stemplot

- D.
Histogram

- E.
Boxplot

- 11.Which one of the following is a FALSE statement about statistical problem solving?
- A.
Each step in statistical problem solving can be manipulated either innocently or deliberately to influence people’s opinion.

- B.
Determining what should be measured is an important part of question formulation.

- C.
Subjects should always be chosen without human subjectivity or bias.

- D.
Numbers should always be reported in context

- E.
Giving measure of confidence is not necessary when reporting results of statistical inference.

- 12.What does the standard deviation of a distribution measure?
- A.
Shape

- B.
Spread

- C.
Center

- D.
Skewness

- 13.Coach Sloan is testing a new method of shooting free throws and plans to randomly assign 20 players to the new method 25 players to the traditional method. The mean percentage of free throws will then be compared between these two groups. What type of study is this?
- A.
An observational study

- B.
A simple random sample

- C.
A matched pairs experiment.

- D.
A completely randomized experiment.

- E.
A randomized block experiment.

- 14.A financial adviser told you that it is better to invest your money in the stock market than putting it in the bank. Assume that the distribution of stock returns is normal with mean µ=10.05% and standard deviation, σ=12.12% per year. Find the proportion of people who invested in the stock market that get less than 8% return on a typical year.
- A.
0.0668

- B.
0.3085

- C.
0.4325

- D.
0.6915

- E.
0.4984

- 15.A researcher wants to know the average dating expenses for BYU single students. The researcher obtained a list of single students from the Records Office who live in the BYU dorms. From this list , 50 students are randomly selected. The 50 students are contacted by phone and the amount they spent on dates are recorded. The average dating expense of the 50 students is $35 with a standard deviation of $8. A critic of the research project argued that the results lack believability because some single students do not live in BYU dorms. This critic is arguing that the study suffers from
- A.
Response bias due to question wording.

- B.
Response bias due to interviewer effect.

- C.
Under-coverage.

- D.
Non-response bias.

- 16.
- Which of the following constitutes a multistage sample 28 elementary school students in the Provo school district?

- A.
Obtain a list of all elementary school students in the Provo school district area; assign consecutive numbers to the students on the list; use a random number table to select 28 students from the list.

- B.
Obtain a list of all elementary school students from each of the 14 elementary schools in the Provo district; use a random number table to select 2 students from each school.

- C.
Randomly select 4 elementary schools in the Provo district; from each of the selected schools randomly select one grade class; from each of the selected classes randomly select 7 students.

- D.
Randomly select 4 schools in the Provo district, from each of the selected schools randomly select one grade class; from each of the selected classes randomly select 7 students.

- 17.The mean points of NBA players is 20 points a game with a standard deviation of 5. The mean points for the PBA (Philippine Basketball Association) is 30 with a standard deviation of 10. Wesley scores 22 points a game for the NBA while Doria scores 31 points a game for the PBA. Who has scores the highest in their league?
- A.
Wesley

- B.
Doria

- C.
They have equal scores

- D.
Cannot be determined from given information.

- 18.When should we use a probability sample?
- A.
So the sample can be used to make inferences about the population.

- B.
Because it is more convenient to use than other types of samples.

- C.
So that bias will be eliminated completely from the sample.

- D.
So that the sample will perfectly represent the population.

- E.
So that sampling variability will be removed.

- 19.A researcher wants to know whether clean air filter improves gas mileage. 10 vehicles were randomly selected. For each vehicle, a coin is tossed. If it is heads, a clean air filter is installed first in the vehicle and the average mileage is computed. After the testing, a dirty air filter is installed and the average mileage is computed. If it is tails, then a dirty air filter is installed first and then a clean air filter is installed next. This study is an example of
- A.
A completely randomized experiment

- B.
A randomized block experiment

- C.
A matched pairs experiment

- D.
An observational study

- E.
A multi-stage sample

- 20.After a Church game, Jeremiah scored 40 points. His coach, who is a Statistics teacher, told him that the standardized score (z-score) for his points on the game, is 2.5. What is the best interpretation of this standardized score?
- A.
Jeremiah’s score is only 2.5

- B.
Only 2.5% of the players scored higher than Jeremiah.

- C.
Jeremiah’s scoring is 2.5 times the average scoring in the league.

- D.
Jeremiah’s scoring is 2.5 standard deviations above the average scoring in the league.

- E.
Jeremiah’s scoring is 2.5 points above the average scoring in the league.

- 21.Coach Sloan is wants to know how different feet positions affect shooting field goal percentage. He randomly assigns 30 players to 3 different feet positions. He compares the field goal percentages among the three groups. This study is an example of
- A.
A completely randomized experiment

- B.
A randomized block experiment

- C.
A matched pairs experiment

- D.
An observational study

- E.
A multi-stage sample

- 22.A study was conducted using growing rats to examine the effect of jumping height on the strength of bones. Thirty rats were randomly allocated into groups. The first group of rats did low jumps of 30 cm. And the second group of rats did high jumps of 60 cm. After 8 weeks of 10 jumps per day, 5 days per week, the bone density of the rats was measured in mg/cm
^{3}. What is the explanatory variable?- A.
Growing rats

- B.
Height of jump

- C.
Bone density as measured in mg/cubic cm.

- D.
Age of rat.

- 23.
- A.
28

- B.
44

- C.
53

- D.
56

- E.
60

- 24.Refer to the histogram below. It is a frequency histogram of Religiosity among 226 randomly selected college students. What is the rough estimate of the standard deviation of the above histogram?
- A.
1

- B.
3

- C.
5

- D.
7

- E.
9

- 25.Refer to the histogram below. It is a frequency histogram of Religiosity among 226 randomly selected college students. How does the mean and median compared for this distribution?
- A.
The mean is less than the median

- B.
The mean is equal to the median

- C.
The mean is greater than the median

- D.
Cannot be determined