Question 1

Which of the following best describes a population in statistics?

Accepted Answer

The entire group of individuals or items that we want information about.

Question 2

A researcher wants to study the average commute time of all employees at a large company. She randomly selects 50 employees from each department and records their commute times. Which sampling technique is she using?

Accepted Answer

Stratified sample

Question 3

Which of the following is a qualitative variable?

Accepted Answer

The favorite color of a group of children

Question 4

A beverage company posts a poll on social media asking people to vote for their favorite flavor. What type of sampling method is this?

Accepted Answer

Convenience sample

Question 5

In the first image, what is misleading about the graphic showing 'The volume of our sales has doubled!'?

Accepted Answer

The graphic uses area to represent a change in volume, exaggerating the increase.

Question 6

Given the following data set of beagle weights (in lbs): 24.6, 24.9, 25.0, 25.3, 25.3, 25.6, 25.7, 25.9, 25.9, 26, 26.1, 26.3, 26.5, 26.5, 26.8, 26.9, 26.9, 27.4, 27.5, 27.8, 27.9, 28.3, 28.5, 28.7, 28.9, 29.2, 29.6, 29.7, 30.6, 30.8. What is the range of the data?

Accepted Answer

$$30.8 - 24.6 = 6.2$$

Question 7

A sample of 325 HCC students has a mean age of 20.7 years. What is this value an example of?

Accepted Answer

A statistic

Question 8

Which of the following best describes a continuous quantitative variable?

Accepted Answer

The weight of a newborn elephant

Question 9

A researcher follows 1,250 people for 3 years to see how their activity level affects blood pressure. What type of study is this?

Accepted Answer

Observational study

Question 10

The heights of newborn giraffes are approximately symmetric with a mean of 69 inches, and 95% of heights are between 63 and 75 inches. What is the standard deviation?

Accepted Answer

$$\frac{75 - 63}{4} = 3$$

Question 11

The weight of newborn elephants is approximately symmetric with $$\mu = 244$$ lbs and $$\sigma = 11$$ lbs. Approximately 68% of newborn elephants are between which two weights?

Accepted Answer

$$244 \pm 11$$ lbs, or 233 lbs to 255 lbs

Question 12

A baby elephant is born weighing 215 lbs. Given $$\mu = 244$$ lbs and $$\sigma = 11$$ lbs, what is the z-score for this elephant? Is this weight unusual?

Accepted Answer

$$z = \frac{215 - 244}{11} = -2.64$$, which is unusual but not very unusual.

Question 13

Match the following scenario: A correlation coefficient of $$r = 1.03 is $$calculated. What does this value indicate?

Accepted Answer

Invalid correlation coefficient

Question 14

A climate researcher records the average yearly temperature and max wind speed from 7 hurricanes and calculates $$r = 0.538. $$Using the provided critical values table, can the researcher claim a linear relationship at $$n = 7$$?

Accepted Answer

No, because $$0.538 \u003c 0.754 ($$the critical value for $$n=7).$$

Question 15

Given the following stem-and-leaf plot for the number of challenge coins owned by secretaries at MacDill AFB, what is the median number of coins owned? (Data: 3, 7, 21, 24, 30, 33, 36, 36, 39, 44, 45, 49, 49, 50, 53, 57, 59, 60, 61, 61)

Accepted Answer

44.5

Question 16

Which of the following best describes the shape of the distribution for the beagle weights at the Fuzzy Wuzzy Vet Clinic?

Accepted Answer

Approximately symmetric

Question 17

A factory tests every 75th can of soup for contamination. What type of sampling method is this?

Accepted Answer

Systematic sample

Question 18

In the second image, what is a potential issue with the line graph showing annual sales of widgets at Company X?

Accepted Answer

The vertical axis does not start at zero, which may exaggerate the increase in sales.

Question 19

If a data set has a mean much higher than the median, what can you infer about the shape of the distribution?

Accepted Answer

The distribution is skewed right.

Unit 1 Review: Understanding Misleading Graphics in Statistics

스터디 가이드 - 연습 문제

학습 가이드 - 플래시카드