AP Stats Final Exam

A consumer group surveyed the prices for a certain item in five different stores, and reported the average price as $15. We visited four of the five stores, and found the prices to be $10, $15, $15, and $25. Assuming that the consumer group is correct, what is the price of the item at the store that we did not visit?

$10

Use Scenario 6-8 The probability is approximately 0.6 that on a randomly selected day the store will make less than which of the following amounts?

$372.60

The weight of written reports produced in a certain department has a normal distribution with mean 60 g and standard deviation 12 g. The probability that the next report will weigh less than 45 g is

.1056

Use Scenario 5-7 The proportion of adults for which the test would be positive is

0.02097

Use Scenario 5-7 If a randomly selected person is tested and the result is positive, the probability the individual has the disease is

0.047

Suppose that A and B are independent events with P(A) = 0.2 and P(B) = 0.4 P(AnB^c)

0.12

Birthweights at a local hospital have a normal distribution with a mean of 110oz and a standard deviation of 15oz. The proportion of infants with birthweights between 125oz and 140oz is about

0.136

Birthweights at a local hospital have a normal distribution with a mean of 110oz and a standard deviation of 15oz. The proportion of infants with birthweights under 95oz is about

0.159

Use Scenario 6-14. If you randomly select 20 bottles from those produced by this machine, what is the approximate probability that exactly 2 caps have been improperly applied?

0.19

Event A has probability 0.4. Event B has probability 0.5. If A and B are disjoint, then the probability that both events occur is

0.2

Use Scenario 6-8 The value of P(X>$400) is

0.2119

Use Scenario 6-14. If you randomly select 20 bottles from those produced by this machine, what is the approximate probability that between 2 and 6 (inclusive) caps have been improperly applied?

0.26

A company produces ceramic floor tiles that are supposed to have a surface area pf 16 square inches. Due to variability in the manufacturing process, the actual surface area has a Normal distribution with a mean of 16.1 square inches and a standard deviation of 0.2 square inches. The proportion of tiles produced by the process with surface area less than 16 square inches is

0.3085

Use Scenario 5-10 The probability that the student takes neither Chemistry nor Spanish is

0.4

Suppose that A and B are independent events with P(A) = 0.2 and P(B) = 0.4 P(AUB)

0.52

Use Scenario 5-10 Find the value of P(AUB) and describe it in words

0.6; The probability that the student takes either chemistry or Spanish, or both.

Use Scenario 6-15.P(X<5)=

0.8704

In a certain game of chance, your chances of winning are 0.2. If you play the game five times and outcomes are independent, which of the following represents the probability that you win at least once?

1-(0.8)^5

A lobster fisherman is keeping track of the productivity of a set of traps he has placed in a favorite location. Below are the numbers of lobsters in these traps over the course of 12 different hauls.

14 only

Use Scenario 6-13. Which of the following is the approximate standard deviation of X?

19

Use Scenario 6-15. The expected value of X is:

2.5

The standard deviation of 16 peoples' weights (in pounds) is computed to be 5.4. The variance of these measurements is

29.16

In a certain town, 60% of the households have broadband internet access, 30% have at least one high-definition television, and 20% have both. The proportion of households that have neither broadband internet nor high-definition television is:

30%

A company produces packets of soap powder that are labelled "Giant Size 32 Ounces" The actual weight of soap powder in a box has a normal distribution with a mean of 33oz. and a standard deviation of 0.7oz. 95% of packets actually contain more than x oz. of soap powder. What is x?

31.85

The mean age of four people in a room is 30 years. A new person whose age is 55 years enters the room. The mean age of the five people now in the room is

35

Students at University X must have one of four class ranks - freshman, sophomore, junior, or senior. At University X, 35% of the students are freshman and 30% are sophomores. If a University X student is selected at random, the probability that he or she is either a junior or a senior is

35%

Use Scenario 6-14. In a production run of 800 bottles, what is the expected value for the number of bottles with improperly applied caps?

40

Use Scenario 6-14. In a production run of 800 bottles, what is the standard deviation for the number of bottles with improperly applied caps?

6.16

Use Scenario 6-13. Which of the following is the mean of X?

600

The heights of American men aged 18 to 24 are approximately Normally distributed with a mean of 68 inches and a standard deviation of 2.5 inches. Only about 5% of young men have heights outside the range

63 inches to 73 inches

Here is a list of scores for Mr. Williams's calculus class: 60 61 61 65 72 75 75 78 81 81 85 89 91 98 What is the percentile of the person whose score was 85?

71%

Use Scenario 3-5 (chapter 3 test paper) Suppose Joe scores a 90 on the first exam. What would be the predicted value of his score on the final exam?

91

The five-number summary for scores on a statistics exam is 11, 35, 61, 70, 79. In all, 380 students took the test. About how many had scores between 35 and 61?

95

The median age of five elephants at a certain zoo is 30 years. One of the elephants, whose age is 50 years, is transferred to a different zoo. The median age of the remaining four elephants is

Cannot be determined from the information given

Which of the following properties is true for all normal density curves? I. They are symmetric II. The curve reaches its peak at the mean III. 95% of the area under the curve is within one standard deviation of the mean

I and II only

Which of the following statements is/are true I correlation and regression requre that there are cleary identified explanatory and response variables II Scatterplots require that both variables be quantitative III every leat-squares regression line passes through (x,y)

II and III only

The histogram below shows the length (in minutes) of 140 songs recorded by the band Wilco.

Skewed right, centered at about 4.5, with several high outliers.

All but one of the following statements contains an error. Which statement could be correct?

The correlation between mid-August soil moisture and per-acre yield of tomatoes is r= 0.53

A set of data has a mean that is much larger than the median. Which of the following statements is most consistent with this information?

The distribution is skewed right.

You are told that your score on an exam is at the 85 percentile of the distribution of scores. This means that

Your score was higher than approximately 85% of the people who took this exam.

A stratified random sample addresses the same issues as which of the following experimental designs?

a block design

all of 33

a block design

To test the effect of music on productivity, a group of assembly line workers are given portable mp3 players to play whatever music they choose while working for one month. For another month, they work without music. The order of the two treatments for each worker is determined randomly. This is

a matched pairs experiment

A simple random sample of size n is defined to be

a sample size of n chosen in such a way that every set of n units in the population has an equal chance to be the sample actually selected

The essential difference between an experiment and an observational study is that

an experiment imposes treatments on the subjects, but an observational study does not

Which of the following is not a major principle of good design for all experiments?

blocking

We say that the design of a study is biased if which of the following is true?

certain outcomes are systemically favored

The most important advantage of experiments over observational studies is that

experiments can give better evidence of causation

You want to use numerical summaries to describe a distribution that is strongly skewed to the left. Which combination of measure of center and spread would be the best ones to use?

median and IQR

A score's percentile is a measure of

relative location

which of the following statements is false?

sophisticated statistical methods can always correct the results if the population you are sampling from is different from the population of interest, for example, due to undercoverage

a sample of student opinion at a big ten university selects an SRS of 200 of the 30,000 undergraduate students and a seperate SRS of 100 of the 5,000 graduate students. This kind of sample is called a

stratified random sample

A community college announces that the correlation between college entrance exam grades and scholastic achievement was found to be -1.08. On the basis of this you would tell the college that

the college should hire a new statistician (impossible)

Use Scenario 3-5 (chapter 3 test paper) The final test score is

the explanatory variable

The correlation coefficient measures

the strength of the linear relationship between two quantitative variables

You measure the age, marital status and earned income of an SRS of 1463 women. The number and type of variables you have measured is

three; one categorical and two quantitative

all of 24

undercoverage