AP Statistics Exam Review

I have a confidence interval that is (22, 26). Assuming the standard deviation is 3 and the sample size is 13, what is the confidence level?

What is the P-value if I have a test statistic of t = 1.632, sample size of 35, and I am doing a two-sided test?

• .1119

• .9440

• .0358

• .1753

What is the critical value (t*) for a sample of 55 for 88% confidence?

• .239

• 1.580

• -1.118

• -2.54

A business evaluates a proposed venture as follows. It stands to make a profit of $10,000 with probability 3/20, to make a profit of $5000 with probability 9/20, to break even with probability 5/20, and to lose $5000 with probability 3/20. The expected profit in dollars is

• 0

• -2050

• 1500

• 3000

Let the random variable X represent the profit made on a randomly selected day by a certain store. Assume that X is Normal with mean $360 and standard deviation $50. What is P(X > $400)?

A bag of candy contains 5 different types of colored candies; red, green, blue, yellow, and orange. According to the manufacturer, bags should contain an equal number of each color. Students in a statistics class decided to use a chi-square procedure to test the manufacturer's claim. They opened a bag of candy and recorded the number of candies of each color. The results are shown in the following table. Which color contributes most to the chi-square test statistic?

Which of the following is the best estimate of the standard deviation of the distribution in the figure?

• 18

• 9

• 54

• 97

• 106

A company wanted to determine the child care costs of its employees. A sample of 25 employees were interviewed and their child care expenses for the previous year were determined. Later, the company discovered that the highest expense in the sample was mistakenly recorded as 5 times the actual amount. However, after correcting the error, the correct amount was still greater than or equal to any other expense in the sample. Which of the following sample statistics must have remained the same after the correction was made?

• standard deviation

• mean

• mode

• range

• median

A company determines the mean and standard deviation of the employees' salaries in one year. What is the best description of the standard deviation?

• Approximately the median distance between the individual salaries of employees and the mean of every employee's salary.

• The amount of money separating the highest salary from the lowest salary when considering the middle 50% of the distribution.

• The amount of money separating the highest salary from the lowest salary when considering all employees.

• The distance between the salary of an employee and the mean salary of all the employees.

• Approximately the mean distance between the individual salaries of employees and the mean of all employees' salaries.

The equation of the LSRL for the points on a scatterplot is ŷ = 5.3-0.23x. What is the residual for the point (5, 4)?

• -0.15

• 0.15

• 1

• 0.62

• 0.85