Question 1

A researcher wants to determine if a new teaching method improves student performance. She randomly assigns students to either the new method or the traditional method and compares their final exam scores. What type of study is this?

Accepted Answer

An experiment

Question 2

A local pet store records the number of items each customer purchases and the time each customer spends in the store. Which of the following is the population in this study?

Accepted Answer

All pet store customers

Question 3

Which of the following best describes a histogram?

Accepted Answer

A graph that displays data using bars to show the frequency of data in equal intervals

Question 4

A study finds the mean monthly utility bill for a sample of homes is $$124 with a standard deviation of 12. $$The distribution is approximately bell-shaped. According to the Empirical Rule, about what percentage of homes have a monthly bill between $$100 and 148$$?

Accepted Answer

$$95\%$$

Question 5

Which measure of center is most resistant to extreme values (outliers)?

Accepted Answer

Median

Question 6

A stem-and-leaf plot of weekly rainfall in inches is given as: 1 | 3 4, 2 | 1 6 9, 3 | 1 7 7 8 9. What is the median weekly rainfall?

Accepted Answer

$$3.1$$ inches

Question 7

A variable that can be counted and only takes on specific values (such as the number of pets) is best described as:

Accepted Answer

Quantitative, discrete

Question 8

A researcher collects data on the heights of 100 students. Which type of graph is most appropriate for displaying this data?

Accepted Answer

Histogram

Question 9

A study reports a sample mean of $$36,300$$ miles for the lifetime of a certain brand of tire. Is this value a statistic or a parameter?

Accepted Answer

Statistic

Question 10

In an experiment, each customer smells two brands of pet shampoo and ranks them on a scale from 1 to 5. Is this a matched pairs or random block design?

Accepted Answer

Matched pairs

Question 11

Which of the following best describes the shape of a distribution that is pulled toward the low tail?

Accepted Answer

Skewed left

Question 12

Given a data set with a mean of $$50$$ and a median of $$48$$, what can you infer about the shape of the distribution?

Accepted Answer

It is skewed right

Question 13

A sample of monthly utility bills is approximately normal with mean $$124$$ and standard deviation $$12. $$What is the z-score for a bill of $$148$$?

Accepted Answer

$$2$$

Question 14

Which of the following is NOT a measure of spread?

Accepted Answer

Mode

Question 15

A scatterplot shows that as temperature increases, the number of cricket chirps per second also increases. What type of association is this?

Accepted Answer

Positive association

Question 16

If the linear correlation coefficient $$r = 0.85$$, what does this indicate about the relationship between two variables?

Accepted Answer

There is a strong positive linear relationship

Question 17

A critical value for the correlation coefficient is $$0.514. If $$the computed $$r = 0.54$$, what can you conclude?

Accepted Answer

There is a significant linear relationship

Question 18

Which of the following statements about correlation and causation is correct?

Accepted Answer

Correlation does not necessarily imply causation

Question 19

A data set has a mean of $$27$$ and a standard deviation of $$5. $$According to the Empirical Rule, approximately what percentage of data falls between $$17$$ and $$37$$?

Accepted Answer

$$68\%$$

Fundamental Concepts and Data Analysis in Introductory Statistics

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