AP Stats Chapter 5 Exam

Suppose that the mean of a set of values is 20, and the standard deviation is 3. If each value is increased by 5, what will be the mean and standard deviation of the new set of values?

• mean = 25, sd = 8

• mean = 20, sd = 3

• mean = 20, sd = 8

• mean = 25, sd = 3

A college offers scholarships to students who score in the top 2% of students on an entrance exam. If the mean score on the exam is 176 and the standard deviation is 4, what is the minimum score a student would need to get a scholarship?

• 167.80

• 184.20

• 176.08

• 179.92

The correlation (r) between high school students' height (in inches) and weight (in pounds) for a large sample of students is found to be 0.3. If the weight measurements are converted to kg, what will be the resulting correlation?

(1 kg = 2.2 lbs)

• 0.3

• 0.66

• -0.3

• 0.136

For a particular value of an explanatory variable, the residual is -0.7. Which of the following is a true statement?

• The regression line underestimates the actual response variable value at this point.

• The regression line overestimates the actual response variable value at this point.

• . A non-linear regression would provide a better fit.

Data is obtained for a large group of college students relating the time they spent writing an essay and the grade on the essay. The equation is grade = 30.18 + 6.49(time) with r = 0.724 What percentage of the variation in grades can be explained by looking at time spent on the essay?

• 52.4%

• 72.4%

• 27.6%

• 47.6%

A college professor asked his students how they feel about this statement: "I like math!" What proportion of women strongly agreed?

• 23.1%

• 57.1%

• 14.6%

• 26.7%

Interpret the circled point on this relative cumulative frequency graph.

• 60% of Starbucks drinks have 30g of sugar.

• 60% of Starbucks drinks have 30g of sugar or more.

• 60% of Starbucks drinks have 30g of sugar or less

• None of these interpretations is correct.

Desiree is interested to see if students who consume more caffeine tend to study more as well. She randomly selects 20 students at her school and records their caffeine intake (mg) and the number of hours spent studying. What is the equation for the LSRL?

• Caffeine = 2.544 + 0.164(hours)

• Hours = 2.544 + 0.164(Caffeine)

• Caffeine = 0.164 + 2.544(hours)

• Hours = 0.164 + 2.544(Caffeine)

Suppose the plot of x vs log y appears linear. What can we conclude about the relationship between the explanatory and response variables?

• A linear model will best fit the original data.

• An exponential model will best fit the original data.

• A power model will best fit the original data.

• It is impossible to determine without examining the data

Scores on the mathematics part of the SAT exam in a recent year were roughly Normal with mean 515 and standard deviation 114. You choose an SRS of 100 students and average their SAT Math scores. Suppose that you do this many, many times. Which of the following are the mean and standard deviation of the sampling distribution of x̄ ?

• Mean = 515; SD = 114

• Mean = 515; SD = 114/√100

• Mean = 515/100; SD = 114/√100

• Mean = 515/100; SD = 114/100

• Mean = 515/100; SD = 114/√100