Q1. Which of these data sets has a higher mean? Higher median? Higher standard deviation? (Do not do any calculations. Just look at the data.)
Q2. Which of these data sets has a higher mean? Higher median? Higher standard deviation? (Do not do any calculations. Just look at the data.)
Q3. Suppose that you have 10 observations that have a mean of 7, a median of 6, and a standard deviation of 3. If you double the value of each observation, what are the new values of the:
a. Mean?
b. Median?
c. Standard deviation?
Q4. Suppose that you have 10 observations that have a mean of 7, a median of 6, and a standard deviation of 3. If you halve the value of each observation, what are the new values of the:
a. Mean?
b. Median?
c. Standard deviation?
Q5. Identify the apparent statistical mistake in this commentary [13]:
The median cost of a house in [Duarte, California] is a whopping $4,276,462, making it the most expensive housing market in the country. It ranks No. 1 on Forbes' annual ranking of America's Most Expensive ZIP Codes.. [O]nly 12homes are currently on the market. So a single high-priced listing (like the mammoth nine-bedroom, built this year, that's selling for $19.8 million) is enough to skew the median price skyward.
Q6. Table 1.4 shows the US dollar prices of Big Mac hamburgers in 20 countries. Use a box plot to summarize these data.
Q7. Figure 3.11 shows two box plots. Which data set has the higher median? The higher standard deviation?
Q8. Figure 3.12 shows two box plots. Which data set has the higher median? The higher mean? The higher standard deviation?
Q9. Use the data in Exercise 3.29 to make a scatter diagram with the P/E ratio on the horizontal axis and the return on the vertical axis. Does there appear to be a positive relationship, negative relationship, or essentially no relationship?
Q10. Explain the error in the conclusion reached by a security analyst [16]:
The Dow Jones Industrial Average peaked at 381.17 during September 3, 1929. The so-called Great Crash pushed this index down 48% by November 13. But, by April17, 1930, the index rebounded 48% from the November bottom. In other words, anyone who bought a diversified portfolio of stocks during September 1929would have experienced no net change in the value of his portfolio by April of1930.
Q11. Use the data in Table 3.2 to determine the percentage annual rate of increase in the CPI between 1990 and 2014.
Q12. A 1989 radio commercial claimed: "If you have a Life Alert security system, your chances of becoming a victim of a serious crime are 3000 to 4000 percent less than your neighbor's." Is this possible?
Q13. Twelve college women and men were asked to read a short article and, when they were finished, estimate how long it took them to read the article. Table 3.7 shows the actual and estimated times (both in seconds) and the percentage difference between the two. Summarize the percentage error data with two side-by-side box plots, one for women and one for men.
Q14. The data in Table 3.10 were used in the 1964 Surgeon General's Report warning of the health risks associated with smoking, where the first variable is annual per capita cigarette consumption and the second variable is deaths from coronary heart disease per 100,000 persons aged 35 to 64. Calculate the correlation. Does the value of the correlation suggest that there is a positive relationship, negative relationship, or essentially no relationship between cigarette consumption and heart disease?
Q15. If y ¼ 10 - 3x, then the correlation between x and y is:
a. 1.
b. 0.
c. 1.
d. Un-defined.
Q16. Explain how the following two newspaper headlines that appeared on the same day could both be accurate: "Orders for Machine Tools Increased 45.5% in October" [19]; "October Orders for Machine Tools Decreased 29%" [20].