Q: A frequency distribution of exam scores is given below: Score Range: 50-59, Frequency: 5 Score Range: 60-69, Frequency: 8 Score Range: 70-79, Frequency: 12 Score Range: 80-89, Frequency: 10 Score Range: 90-99, Frequency: 5 What percentage of students scored at least 80?

$$\frac{15}{40} \times 100\% = 37.5\%$$

Question 1

A researcher wants to estimate the average number of hours university students spend studying per week. She randomly selects 200 students from her university and records their study hours. Which of the following best describes the sample and the population in this scenario?

Accepted Answer

The sample is the 200 students selected; the population is all university students at her university.

Question 2

Which of the following variables is quantitative and continuous?

Accepted Answer

The height of a plant measured in centimeters.

Question 3

A company wants to survey customer satisfaction by randomly selecting 10 blocks in a city and surveying all households in those blocks. What type of sampling is this?

Accepted Answer

Cluster sampling

Question 4

Given the following frequency distribution of days customers waited for a table at a restaurant:

Monday: 2
Tuesday: 4
Wednesday: 6
Thursday: 8
Friday: 14

What is the relative frequency for Thursday?

Accepted Answer

$$\frac{8}{34}$$

Question 5

A histogram of test scores is skewed right. Which measure of central tendency will likely be greater than the others?

Accepted Answer

The mean will be larger than the median.

Question 6

A researcher collects data on the weights of 100 M&M candies and finds the mean is 0.91 g with a standard deviation of 0.04 g. Using the Empirical Rule, what percentage of candies are expected to have weights between 0.87 g and 0.95 g?

Accepted Answer

$$95\%$$

Question 7

Which of the following best describes the difference between an observational study and a designed experiment?

Accepted Answer

An observational study does not impose treatments, while a designed experiment does.

Question 8

A frequency distribution of exam scores is given below:

Score Range: 50-59, Frequency: 5
Score Range: 60-69, Frequency: 8
Score Range: 70-79, Frequency: 12
Score Range: 80-89, Frequency: 10
Score Range: 90-99, Frequency: 5

What percentage of students scored at least 80?

Accepted Answer

$$\frac{15}{40} 	imes 100\% = 37.5\%$$

Question 9

Which of the following statements about the standard deviation is correct?

Accepted Answer

The standard deviation measures the spread of the data around the mean.

Question 10

A boxplot shows that the median is closer to the lower quartile and the upper whisker is much longer than the lower whisker. What does this indicate about the distribution?

Accepted Answer

The distribution is skewed right.

Question 11

A survey asks respondents to report their favorite type of cuisine. What type of variable is this?

Accepted Answer

Qualitative, categorical

Question 12

A researcher wants to compare the heights of male and female students. She collects data and finds the following:

Mean height (males): 175 cm, SD: 7 cm
Mean height (females): 165 cm, SD: 6 cm

Which group has more relative variability in height?

Accepted Answer

Females, because their coefficient of variation is higher.

Question 13

A company wants to ensure their survey results are not biased. Which of the following is an example of sampling bias?

Accepted Answer

Surveying only customers who visit the store on weekends.

Question 14

Which of the following is a real-life example of a discrete quantitative variable?

Accepted Answer

The number of books a student owns.

Question 15

A relative frequency histogram is constructed for the following data:

Class: 10-19, Relative Frequency: 0.2
Class: 20-29, Relative Frequency: 0.5
Class: 30-39, Relative Frequency: 0.3

What is the total number of observations if there are 40 data points?

Accepted Answer

40

Question 16

A pie chart is used to display the proportion of students in different majors. Which of the following is a limitation of using a pie chart?

Accepted Answer

It cannot show the actual number of students.

Question 17

A researcher wants to determine if there is a relationship between exercise habits and eating habits among adults. What type of study design is most appropriate?

Accepted Answer

Observational study

Question 18

Which of the following best describes the median?

Accepted Answer

The middle value when the data are ordered from least to greatest.

Question 19

A researcher finds that the interquartile range (IQR) for a data set is 12. What does this indicate?

Accepted Answer

The difference between the first and third quartiles is 12.

Fundamentals of Statistics: Data Types, Sampling, Frequency Distributions, and Measures of Central Tendency

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