One Variable and Two Variable Statistics

What is a correlation coefficient?

• Number between 0 and 1 that describes the strength of a relationship

• Number between -1 and 1 that describes the strength of a relationship

• The type of relationship; positive, negative or none.

• The category of confusion with trend lines

The plot shows the residuals when a line is fit to a set of data. Based on the residual plot, which statement best describes how well the line fits the data?

• The line is a good fit because the residuals are all close to the x-axis and are randomly distributed about the x-axis.

• The line is not a good fit because the residuals are not all close to the x-axis.

• The line is not a good fit because the residuals are not randomly distributed about the x-axis.

• The line is not a good fit because the residuals are not all close to the x-axis and are not randomly distributed about the x-axis.

Which of the following correlation coefficients indicate a strong linear correlation?

• −0.872691

• −0.658799

• −0.125866

• 0.989862

• 0.798264

Which of the following statements are supported by the survey data in the two-way frequency table?

• The joint relative frequency that a person surveyed is female and left-handed is about

  0.168, or 16.8%.

• The conditional relative frequency that a person surveyed is female, given that the person is right-handed, is about 0.4907, or 49.07%.

• The joint relative frequency that a person surveyed is male and is right-handed is about 0.41, or 41%.

• The conditional relative frequency that a person surveyed is right-handed, given that the person is male, is about 0.5093, or 50.93%.

• The marginal relative frequency that a person surveyed is left-handed is about 0.195, or 19.5%.

Susan measures her son Jeremy’s height at various ages. The results are shown below. Which of the following is a statement of causation?

• When Jeremy was 13 years old, he was 62 inches tall.

• There appears to be a relationship between Jeremy’s age and height.

• As Jeremy’s age increases, his height also increases.

• Jeremy’s age affects his height.

Pick the definition of an outlier.

• A value that lies outside of most other values in a data set.

• A value that is the largest.

• A value that is the smallest.

• A value that occurs the most.

True or False: the mean and median values of shoe sizes shown in the dot plot for Group B are almost the same.

• True

• False

In a population of five university students with GPAs of 2.5, 2.3, 1.7, 1.4, and 1.1, a sample of three students are considered. What would be the standard deviation of the resulting sampling distribution?

• 0.53

• 0.41

• 0.35

• 0.22

On a recent test, a statistics professor finds that the mean and median scores are nearly equal. Which of the following could be the distribution of test scores?

• 
• 
• 
• None of these is correct

Which restaurant has a greater IQR?

• Lucy's Steakhouse

• Gary's Grill

• They are the same