Question 1

Which of the following best describes the variable 'Number of children' in a household?

Accepted Answer

Quantitative, discrete

Question 2

A researcher surveys every 10th person on a list after randomly selecting a starting point. What sampling method is being used?

Accepted Answer

Systematic sampling

Question 3

Given the following data set: 20, 13, 4, 8, 10, what is the sample mean?

$$	ext{Sample mean} = \frac{20 + 13 + 4 + 8 + 10}{5}$$

Accepted Answer

$$11$$

Question 4

In the table of responses to road construction funding, what percent of respondents preferred an increase in gas tax?

$$	ext{Percent} = \frac{181}{412 + 181 + 412} 	imes 100$$

Accepted Answer

$$22\%$$

Question 5

Which of the following is a parameter?

Accepted Answer

The average score for a class of 28 students taking a calculus midterm exam

Question 6

Which of the following variables is best classified as continuous?

Accepted Answer

Annual household income

Question 7

A news outlet surveys people at a busy intersection to predict election results. What sampling method is this?

Accepted Answer

Convenience sampling

Question 8

Using the empirical rule, what percentage of people have an IQ score between 70 and 130 if the mean is 100 and the standard deviation is 15?

Accepted Answer

$$95\%$$

Question 9

Given the Yelp ratings for Hot Doug’s, what is the mode of the ratings?

Accepted Answer

5 Stars

Question 10

For the Yelp ratings for Hot Doug’s, what percentage of ratings are 5 Star ratings?

$$	ext{Percent} = \frac{1675}{35 + 67 + 246 + 724 + 1675} 	imes 100$$

Accepted Answer

$$62\%$$

Question 11

Given the five-number summary: Min = 3, $$Q_1 = 6$, Median = 9, Q_3$ = 12$$, Max = 20, are there any outliers in the data set?

Accepted Answer

No outliers

Question 12

A sample of failure times (in millions of cycles) for Material A is: 3.17, 4.31, 4.52, 4.66, 5.69. What is the sample mean?

$$\bar{x} = \frac{3.17 + 4.31 + 4.52 + 4.66 + 5.69}{5}$$

Accepted Answer

$$4.87$$

Question 13

Which of the following best describes the shape of the Yelp ratings distribution for Hot Doug’s?

Accepted Answer

Skewed left

Question 14

Given the data set: 5, 20, 15, 25, 0, 10, 15, 5, 25, 30, 20, what is the median?

Accepted Answer

$$15$$

Question 15

If the interquartile range (IQR) is 6, $$Q_1 = 6$, and Q_3$ = 12$$, what is the upper fence for outlier detection?

$$	ext{Upper fence} = Q_3$ + 1.5 	imes IQR$$

Accepted Answer

$$21$$

Question 16

A simple random sample is best described as:

Accepted Answer

Selecting individuals so that every possible sample has an equal chance of being chosen

Question 17

Which of the following is a statistic?

Accepted Answer

The mean cholesterol level from a random sample of patients

Question 18

Given the data: 28, 39, 42, 29, 39, 40, 36, 46, 41, 30, what is the mode?

Accepted Answer

$$39$$

Question 19

Which sampling method involves dividing the population into groups based on a characteristic and then randomly sampling from each group?

Accepted Answer

Stratified sampling

Question 20

If a variable can take on any value within a given range, it is best described as:

Accepted Answer

Continuous

Introductory Statistics Study Guide: Frequency Distributions, Graphs, and Descriptive Statistics

Study Guide - Practice Questions