AP Stat Unit 8

The mean number of accidents a week at a company is 6.4 with a standard deviation of 1.5. What proportion of weeks would you expect to have more than 7 accidents?

• 0.3446

• 0.2856

• 0.4

• 0.6554

For the density curve shown, which of the following statements is true?

• The mean is larger than the median.

• The proportion of outcomes between 0.2 and 0.5 is equal to 0.3.

• The total area under the curve is greater than 1.

• The proportion of outcomes greater than 1.5 is equal to 0.25.

The graph below is a Normal probability plot of test scores for students in Mr. Olivier’s precalculus classes. Based on this plot, which of the following is the best conclusion about the distribution of test scores?

• Since the Normal probability plot is curved the distribution of test scores is approximately Normal.

• Since the Normal probability plot is curved the distribution of test scores is not approximately Normal.

Jorge's score on Exam 1 in his statistics class was at the 64th percentile of the scores for all students. His score falls

• between the minimum and first quartile

• between the first quartile and the median

• between the median and the third quartile

• between the third quartile and the maximum

• at the mean score for all students

Fuji apples grown at a certain orchard have a mean weight of 5.2 ounces with a standard deviation of 0.8 ounces. Suppose the scale the orchard owner uses systematically underweighs apples by 0.2 ounces and also weighs the apples in grams, rather than ounces. What would the mean and standard deviation of these apples’ weights be as determined by this scale? (Note: 1 ounce ≈ 28 grams).

• Mean 145.6 grams, standard deviation 22.4 grams.

• Mean 140 grams, standard deviation 22.4 grams.

• Mean 140 grams, standard deviation 16.8 grams.

Given the probabilities P(A) =0.4 and P(A∪B) =0.6, what is the probability P(B): If A and B are mutually exclusive? If A and B are independent?

• 0.2; 0.4

• 0.2; 0.33

• 0.33; 0.2

• 0.6; 0.33

If P(A) = 0.34 and P(A or B) = 0.71, which of the following is false?

• P(B) = 0.37, if A and B are disjoint.

• P(B) = 0.561, if A and B are independent.

• Cannot be determined if A and B are neither disjoint nor independent.

• P(A∣B)= 0.34, if A and B are independent.

P(Freshman or Pizza):

• 27/50

• 4/50

• 3/50

• 30/50

P(Pizza ∩ Water) =

• 62/182

• 120/400

• 58/400

• 140/400

P(Sandals|Pants):

• 4/20

• 6/15

• 1/2

• 2/7