Q: Refer to the pie chart showing MathNet stock price changes over 300 days. How many days did the stock price go up?

$$300 \times 0.4333 = 130$$ days

Q: Refer to the relative frequency histogram of wait times at a restaurant. If the sample represented 500 customers, how many waited between 22 and 24 minutes?

$$500 \times 0.15 = 75$$ customers

Q: Given the bar graph of political views, what percentage of students responded 'Moderate'?

$$\frac{12}{30} \times 100\% = 40\%$$

Question 1

A recent survey of 2041 American college students indicated that 20% of them lived at home during their first year of college and that they spent an average of $$413 on textbooks during their first year. Which of the following best describes the value 413$$?

Accepted Answer

It is a statistic because it describes a sample.

Question 2

Which of the following variables is both quantitative and continuous?

Accepted Answer

Time it takes to complete a puzzle in minutes

Question 3

What is the level of measurement for the variable 'Temperature of a lake'?

Accepted Answer

Interval

Question 4

A mathematics department polls 25 faculty and 25 students. What type of sampling is this?

Accepted Answer

Stratified sampling

Question 5

Refer to the pie chart showing MathNet stock price changes over 300 days. How many days did the stock price go up?

Accepted Answer

$$300 	imes 0.4333 = 130$$ days

Question 6

Based on the boxplot of monthly rent, which of the following statements is correct?

Accepted Answer

The median monthly rent is approximately $450.

Question 7

Given the boxplot for the number of books read over the summer, what is the value of $$Q_1$$ and what does it represent?

Accepted Answer

$$Q_1 = 4$, meaning 25% of students read 4 or fewer books.

Question 8

Refer to the relative frequency histogram of wait times at a restaurant. If the sample represented 500 customers, how many waited between 22 and 24 minutes?

Accepted Answer

$$500 	imes 0.15 = 75$$ customers

Question 9

Which of the following best describes the shape of the wait time distribution shown in the histogram?

Accepted Answer

Right-skewed

Question 10

Given the bar graph of political views, what percentage of students responded 'Moderate'?

Accepted Answer

$$\frac{12}{30} 	imes 100\% = 40\%$$

Question 11

A data set has mean $$15.8$$ and median $$6.5. $$What is the likely shape of the distribution?

Accepted Answer

Right-skewed

Question 12

A student scored 610 on the SAT (mean 515, SD 114) and 27 on the ACT (mean 21, SD 5.1). Which score is relatively better?

Accepted Answer

ACT, because $$z = \frac{27-21}{5.1} = 1.18$$

Question 13

If the mean selling price of used cars is $$10,178 with a standard deviation of 3$$,074$$, what percentage of cars sell for between 4$$,030$$ and 16$$,326$ according to Chebyshev's Theorem?

Accepted Answer

At least 75%

Question 14

A 10-year-old girl is in the 30th percentile for height at 53.2 inches. What does this mean?

Accepted Answer

She is as tall or shorter than 30% of 10-year-old girls.

Question 15

Given the frequency histogram of HDL cholesterol levels, what is the mode of the data set?

Accepted Answer

51 mg/dL

Question 16

Which of the following is an example of a response bias?

Accepted Answer

A survey question is worded in a way that leads respondents to a particular answer.

Question 17

If a data set has a mean of $$11.33$$, a median of $$8.93$$, and a standard deviation of $$5.90$$, what is the interquartile range (IQR)?

Accepted Answer

$$7.87$$

Question 18

Suppose a medication price of $$24.37 is incorrectly recorded as 244.37. $$How does this affect the mean and median?

Accepted Answer

The mean increases significantly, but the median remains unchanged.

Question 19

A light bulb has a mean life of $$450$$ hours and a standard deviation of $$73$$ hours. According to the Empirical Rule, 99.7% of bulbs have lifetimes between which two values?

Accepted Answer

$$231$$ and $$669$$ hours

Introductory Statistics Exam 1 Review – Guided Study Notes

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