AP STATS - review test 2

A researcher is studying a group of field mice. The distribution of weight of field mice is approximately normal with a mean of 25 grams and standard deviation 4 grams. Which of the following is closest to the proportion of field mice with a weight greater than 33 grams?

0.023

A producer supplier ships boxes of produce to individual customers. The distribution of weights shipped boxes is approximately normal with a mean of 36 pounds and a standard deviation of 4 pounds. Which expression represents the weight at the 75th percentile of the distribution?

0.67(4) + 36

The distribution of monthly rent for one bedroom apartments in a city is approximately normal with mean $936 and standard deviation $61. A graduate student is looking for a one bedroom apartment and wants to pay no more than $800 in monthly rent. Of the following, which is the best estimate of the percent of one bedroom apartments in the city with a monthly rent of at most $800?

1.3%

The amount of time required for each of 100 mice to navigate through a maze was recorded. The histogram below shows the distribution of times in seconds for the 100 mice. Which of the following values is closest to the standard deviation of the 100 times?

10 seconds

A candy company produces individually wrapped candies. The quality control manager for the company believes that the weight of the candies is approximately normally distributed with a mean of 720 milligrams. If the manager's belief is correct, which of the following intervals of weights will contain the largest proportion of the candies in the distribution of weights?

700 mg to 740 mg

Some descriptive statistics for a set of test scores are shown in the table above. For this test, a certain student has a standardized score of z = -1.2. What score did this student receive on the test?

779.42

The distribution of weights of female college cross country runners is approximately normal with mean 122 pounds and standard deviation 8 pounds. Which of the following is closest to the percent of the runners who weigh between 114 pounds and 138 pounds?

82%

A distribution of test scores is not symmetric. Which of the following is the best estimate of the z-score of the third quartile?

The z-score cannot be estimated from the information given.

The commuting time for a student to travel from home to college campus is normally distributed with a mean of 30 minutes and a standard deviation of 5 minutes. If the student leaves home at 8:25 a.m., what is the probability that the student will arrive at the college campus later than 9 a.m.?

0.16

At a small coffee shop, the distribution of the number of seconds it takes for a cashier to process an order is approximately normal with a mean of 276 seconds and a standard deviation of 38 seconds. Which of the following is closest to the proportion of orders that are processed in less than 240 seconds?

0.17

The caffeine content of 8 ounce cans of a certain cola drink is approximately normally distributed with mean 33 milligrams. A randomly selected can containing 35 milligrams of caffeine is 1.2 standard deviations above the mean. Approximately what percent of 8 ounce cans of the cola have a caffeine content greater than 35 mg?

12%

For a certain online store, the distribution of number of purchases per hour is approximately normal with mean 1200 purchases and standard deviation 200 purchases. For what proportion of hours will be the number of purchases at the online store exceed 1400?

16%

Shalise completed a jigsaw puzzle competition where participants are timed on how long they take to complete puzzles of various sizes. Shalise completed a small puzzle in 75 minutes and a large jigsaw puzzle in 140 minutes. For all participants, the distribution of completion time for the small puzzle was approximately normal with a mean of 60 minutes and standard deviation 15 minutes. The distribution of completion time for the large puzzle was approximately normal with a mean of 180 minutes and standard deviation 40 minutes. Approximately what percent of the participants had finishing times greater than Shalises's for each puzzle?

16% on the small puzzle and 84% on the large puzzle

A sleep time of 15.9 hours per day for a newborn baby is at the 10th percentile of the distribution of sleep times for all newborn babies. Assuming the distribution is normal with standard deviation 0.5 hour, approximately what is the mean sleep time for newborn babies?

16.5

At a certain store, the distribution of weight of cartons of large eggs is approximately normal with a mean of 26 ounces. Based on the distribution, which of the following intervals will contain the greatest proportion of cartons of large eggs at the store?

24 oz to 28 oz

The distribution of lengths of salmon from a certain river is approximately normal with standard deviation 3.5 inches. If 10 percent of the salmon are longer than 30 inches, which of the following is closest to the distribution?

26 inches

The weight of adult male grizzly bears living in the wild in the U.S. is approx. normally distributed with a mean of 500 pounds and standard deviation of 50 pounds. The weight of adult female grizzly bears is approx. normal with a mean of 300 pounds and standard deviation of 40 pounds. Approximately, what would be the weight of a female grizzly bear with the same standardized score as a male grizzly bear with a weight of 530 pounds?

324 pounds

The height of 3 year old boys is approximately normally distributed. Duncan and Shane are 3 year old boys. Duncan is 32.0 inches tall and is at the 32nd percentile of the distribution. Shane is 34.0 inches tall and is at the 62nd percentile of the distribution. Which of the following is closest to the mean of the height distribution?

33.21 inches

For a recent season in college football, the total number of rushing yards for that season is recorded for each running back. The mean number is 790 yards. One running back had 1,637 rushing yards for the season, which is 2.42 standard deviations above the number of rushing yards. What is the standard deviation of the number of rushing yards for the running backs that season?

350 yards

The distribution of assembly times required to assemble a certain smartphone is approximately normal with mean 4.6 minutes and standard deviation 0.6 minutes. Of the following, which is closest to the percentage of assembly times between 4 minutes and 5 minutes?

59%T

The height of adult women are approximately normally distributed about a mean of 65 inches with a standard deviation of 2 inches. If Rachael is at the 99th percentile in height for adult women, then her height, is closest to:

70

The distribution of heights of 6 year old girls in approximately normally distributed with a mean of 46 inches and a standard deviation of 2.7 inches. Aliyaah is 6 years old, and her height is .96 standard deviations above the mean. Her friend Jayne is also 6 years old and is at the 93rd percentile of the height distribution. At what percentile is Aliyaah's height, and how does her height compare to Jayne's?

Aliyaah's height is at the 83rd percentile of the distribution, and she is shorter than Jayne.

A certain type of remote control car has a fully charged battery at the time of purchase. The distribution of running times of cars of this type is approximately normal with a mean of 80 minutes and a standard deviation of 2.5 minutes. The shaded area in the figure below represents which of the following probabilities?

The probability of running time of a randomly selected car of this type, before it requires recharging of the battery for the first time after its period of initial use, is between 75 minutes and 82.5 minutes.

At a college the scores of the chemistry final exam are approximately normally distributed, with a mean of 75 and a standard deviation of 12. The scores on the calculus final are also approximately normally distributed, with a mean of 80 and a standard deviation of 8. A student scored 81 one the chemistry final and 84 on the calculus final. Relative to the students in each respective class, in which subject did this student do better?

The student did equally well in each course.

Height, in meters, is measured for each person in a sample. After the data is collected, all the height measurements are converted from meters to centimeters by multiplying each measurement by 100. Which of the following statistics will remain the same for both units of measure?

The z-scores of the height measurements

In a large set of data that are approximately normally distributed, r has a z-score of -1.00 s is the value in the first quartile t is the value of the 20th percentile Which of the following is the correct order from least to greatest for the values of r,s,t?

r,t,s

Students in a large psychology class measured the time in seconds it took each of them to perform a certain task. The times were later converted to minutes. If a student had a standardized score of z = 1.72 before the conversion, what is the standardized score for the student after the conversion?

z = 1.72