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Problem 2.3.19
In Exercises 17–20, identify how the graph is deceptive.
Cost of Giving Birth According to the Agency for Healthcare Research and Quality Healthcare Cost and Utilization Project, the typical cost of a C-section baby delivery is $4500, and the typical cost of a vaginal delivery is $2600. See the following illustration.
Problem 2.3.22
V and Digital Ads Listed below are amounts (billions of dollars) spent on TV and digital advertising. The amounts are listed in order by year ending with the year 2022. The last few years are projected amounts (based on data from Magna Global). Construct a graph that reveals the story that the data are trying to tell. What story does the graph depict?
TV Ads:
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Problem 2.4.6
Airport Data Speeds Listed below are the cellular data speeds (Mbps) from Sprint and Verizon measured at nine different airports (based on data from CNN). What would the presence of a correlation suggest about Sprint and Verizon?
Problem 2.4.10
Use Table 2-11 to find the critical values of r. Based on a comparison of the linear correlation coefficient r and the critical values, what do you conclude about a linear correlation?
Using the data from Exercise 6 “Airport Data Speeds,” the linear correlation coefficient is r = 0.866
Problem 2.4.2
Causation A study has shown that there is a correlation between body weight and blood pressure. Higher body weights are associated with higher blood pressure levels. Can we conclude that gaining weight is a cause of increased blood pressure?
Problem 2.4.4a
Estimating r For each of the following, estimate the value of the linear correlation coefficient r for the given paired data obtained from 50 randomly selected adults.
a. Their heights are measured in inches and those same heights are recorded in centimeters .
Problem 2.4.4c
Estimating r For each of the following, estimate the value of the linear correlation coefficient r for the given paired data obtained from 50 randomly selected adults.
c. Their pulse rates are measured and their IQ scores are measured .
Problem 2.4.4d
Estimating r For each of the following, estimate the value of the linear correlation coefficient r for the given paired data obtained from 50 randomly selected adults.
d. The 50 adults all drove cars from Jacksonville, Florida, to Richmond, Virginia. Their average (mean) speeds are recorded along with the times it took to complete that trip.
Problem 2.4.14
In Exercises 13–16, write a statement that interprets the P-value and includes a conclusion about linear correlation.
Using the data from Exercise 6 “Airport Data Speeds,” the P-value is 0.003.
Problem 3.2.23
In Exercises 21–24, find the coefficient of variation for each of the two samples; then compare the variation. (The same data were used in Section 3-1.)
Pulse Rates Listed below are pulse rates (beats per minute) from samples of adult males and females (from Data Set 1 “Body Data” in Appendix B). Does there appear to be a difference?
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