BackCrime Rate and Cell Phones The linear correlation between violent crime rate and percentage of the population that has a cell phone is −0.918 for years since 1995. Do you believe that increasing the percentage of the population that has a cell phone will decrease the violent crime rate? What might be a lurking variable between percentage of the population with a cell phone and violent crime rate?
Graphical Analysis In Exercises 11–14, determine whether there is a perfect positive linear correlation, a strong positive linear correlation, a perfect negative linear correlation, a strong negative linear correlation, or no linear correlation between the variables.
"[APPLET] Registered Nurse Salaries In Exercises 27–30, use the table, which shows the years of experience of 14 registered nurses and their annual salaries (in thousands of dollars). (Adapted from Payscale, Inc.)
27. Correlation Using the scatter plot of the registered nurse salary data shown below, what type of correlation, if any, do you think the data have? Explain.
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The table shows the mean driving speed of drivers in a 55mph zone and the number of speeding tickets they've received in the past 10 years. Plot the data in a scatterplot with speed on the x-axis. What can you determine about the relationship between mean speed and the number of speeding tickets?
When preparing a scatterplot, which variable is typically placed on the horizontal () axis?
Which of the following best describes the relationship between two variables in a scatterplot that shows points closely clustered around a straight line that slopes upward from left to right?
When examining a scatterplot, how can you determine if there is a relationship between two variables?
Which of the following best describes a scatterplot and its primary use in statistics?
Which of the following scatterplots best shows an outlier in both the - and -direction?
Which of the following scatterplots best illustrates an outlier that is extreme in both the - and -direction?
When comparing the boxplots of two groups, which of the following should be done?
Given several scatterplots, which of the following statements about the calculated correlation coefficient is correct?