Q: In a survey of 703 workers, 61% said they got their jobs through networking. How many workers is this?

$$703 \times 0.61 = 429.83 \approx 430$$

Question 1

Based on the National Health Interview Survey of about 30,000 adult Americans, it was concluded that about 12.5% of all adult Americans smoked one or more cigarettes in the past week. In this context, what is the population parameter?

Accepted Answer

The 12.5% of all adult Americans who smoked in the past week

Question 2

A study of 106 adult subjects showed that their average (mean) body temperature was 98.2°F. What is the sample statistic in this study?

Accepted Answer

The mean body temperature of 98.2°F

Question 3

In a Pew Research Center poll of 1501 randomly selected adults in Latin America, 77% said that global warming is already harming people around the world. The margin of error is 2 percentage points. What is the confidence interval for the proportion?

Accepted Answer

$$77\% \pm 2\% = (75\%, 79\%)$$

Question 4

A total of 106 randomly selected adults are tested for their body temperatures. The estimated mean is 98.2°F with a margin of error of 0.1°F. What is the confidence interval for the mean?

Accepted Answer

$$(98.1^\circ F, 98.3^\circ F)$$

Question 5

In a survey, 70% of respondents said they voted, but actual records show only 61% did. What is the most likely explanation for this discrepancy?

Accepted Answer

Some respondents may have given socially desirable answers rather than the truth.

Question 6

A survey of 22,000 high school students found that 39% reported being tired on most school days, with a margin of error less than 0.1 percentage point. Can we safely conclude that fewer than half of all students say they are tired on most days?

Accepted Answer

Yes, because 39% is well below 50% and the margin of error is very small.

Question 7

Which sampling method is used when every 100th phone number from a list is selected?

Accepted Answer

Systematic sampling

Question 8

A researcher summarizes hundreds of studies on the link between power lines and cancer. What type of study is this?

Accepted Answer

Meta-analysis

Question 9

Which of the following is a quantitative variable?

Accepted Answer

Blood alcohol concentration (BAC)

Question 10

The number of commercial aircraft in the air at any point in time is an example of what type of data?

Accepted Answer

Discrete quantitative data

Question 11

A Visa bill for $$512.50 includes an invalid charge of 8.00. $$What is the relative error?

Accepted Answer

$$\frac{8.00}{504.50} \approx 0.0159$$

Question 12

A car weighs 3440 pounds. One scale reads 3450 pounds (nearest 10 pounds), another reads 3428.8 pounds (nearest 0.1 pound). Which measurement is more precise, and which is more accurate?

Accepted Answer

3428.8 pounds is more precise; 3440 pounds is more accurate.

Question 13

Express $$\frac{3}{5} as a $$decimal and a percentage.

Accepted Answer

$$0.6$$ and $$60\%$$

Question 14

In a survey of 703 workers, 61% said they got their jobs through networking. How many workers is this?

Accepted Answer

$$703 	imes 0.61 = 429.83 \approx 430$$

Question 15

If the population of Montana is 20% less than New Hampshire, Montana's population is what percent of New Hampshire's population?

Accepted Answer

$$80\%$$

Question 16

Given the following pulse rates: 83, 88, 120, 64, 69, 71, 76, 74, 75, 76, 75, 75, 79, 80, 78, 83, 77, 71, 83, 80, 73, 72, 82, 74, 84, 90, 89, 81, 81, 90, 79, 92, 82, 89, 82, 74, 86, 76, 81, 75, 75, 77, 70, 75, 64, 73, 74, 71, 94. Which graphical method would best display the distribution?

Accepted Answer

Stem-and-leaf plot

Question 17

Refer to the bar graph of median home prices in U.S. regions. What is a potential issue with interpreting this graph?

Accepted Answer

The vertical axis does not start at zero, which can exaggerate differences.

Question 18

Refer to the illustration of daily oil consumption in the U.S. and Japan. What is a potential problem with this visual representation?

Accepted Answer

The sizes of the barrels exaggerate the difference by using area or volume instead of height.

Unit 1 Review: Foundational Statistics Concepts and Data Interpretation

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