AP Stats Final

The scores on a university examination are normally distributed with a mean of 62 and a standard deviation of 11. If the bottom 5% of students will fail the course, what is the lowest mark that a student can have and still be awarded a passing grade?

44

A medical researcher collects health data on many women in each of several countries. What % of Country A women weigh between 110 and 240 pounds?

50%

A florist wanted to investigate whether a new powder added to the water of cut flowers helps to keep the flowers fresh longer than just water alone. Which of the following is the best description of the method used by the florist?

An experiment with a completely randomized design.

Which of the following is the best description of a positive association between two variables?

As the value of one of the variables increases, the value of the other variables tend to increase

Three brands of candy piece - X, Y, and Z- are made in many colors. Which of the following statements must be true?

For Brand Y, there were more red candy pieces than green candy pieces in the bag.

A local television news station includes a viewer survey question about a current issue at the beginning of every evening news broadcast

I, II, and III

Jack and Jill are both enthusiastic players of a certain computer game. Who won the contest, and what were each of their z-scores?

Jack's z= 1.07; Jill's z=0.90; Jack wins the contest

Mateo plays on his high school basketball team. Which of the following assignments of the digits 0 to 9 could be used for the simulation?

Let the digits 0 to 9 represent making a basket and the digits 7 to 9 represent not making a basket.

A policeman records the speeds of cars on a certain roadway with a radar gun. Which of the following measures of center and spread would be the best ones to use when summarizing the data?

Mean and standard deviation

Events D and E are independent, with P(D)=0.6 and P(D and E)=0.18 Which of the following is true?

P(D or E)=0.72

An experiment will be conducted to determine whether children learn their multiplication facts better by practicing with flash cards or by practicing on a computer. Why will it be impossible to conduct a double-blind experiment?

The experimenter will know whether the child is a boy or a girl and whether he or she used flash cards or the computer.

A set of bivariate data was used to create a least-squares regression line. Which of the following is minimized by the line?

The sum of the squared residuals

Birthweights at a local hospital have a Normal distribution with a mean of 110 oz. and a standard deviation of 15 oz. Which of the following is the proportion of infants with birthweights under 95 oz?

0.160

If two candies are randomly drawn from the bag with replacement, what is the probability that they are the same color?

0.22

The probability that a new microwave oven will stop working in less than two years is .05, given that a new microwave oven is damaged during delivery. What is the probability that it stops working in less than two years?

0.40

The table shows several values of x and their corresponding values of y. Which of the following is closest to the correlation between x and y?

0.98

A lobster fisherman is keeping track of the productivity of a set of traps he has placed in a favorite location. According to the 1.5 X IQR rule, which values in the above distribution are outliers?

14 only

A grade of C or C+ is assigned to a student who scores between 55 and 70. The percentage of students who obtained a grade of C or C+ is

20%

A dog food company wishes to test a new high-protein formula for puppy food to determine whether it promotes faster weight gain than the existing formula for that puppy food. Which of the following strategies is most appropriate for accomplishing this?

Block on dog breed and randomly assign puppies to existing and new formula groups within each breed.

Some contact lens wearers report problems with dryness in their eyes. Which of the following best explains why the study does not support such a conclusion?

The study had no control group.

A researcher collected data on the age, in years, and the growth of sea turtles. The following graph is a residual plot of the regression of growth versus age.

No, because the graph displays a U-shaped pattern.

At right are box plots describing the distribution of prices paid for homes in two suburbs of Columbus, Ohio over a single 30-day period in 2012. Which of the following statements is supported by the information in this graph?

The median house place in Dublin is higher than the 75th percentile of house price in Westerville.

As part of a study on facility needs, the administration of a university wanted to estimate the percent of students who use the exercise facilities on a regular basis. What are the population and the sample of the study?

The population is the 34,000 students who attend the university, and the sample is the 493 students who indicated that they use the exercise facilities on a regular basis.

As a promotion, the first 50 customers who entered a certain store at a mall were asked to choose from one of two discounts. Are F and S mutually exclusive?

Yes, because P(F and S)=0

A polling form is interested in surveying a representative sample of registered voters in the US. Which of the following is NOT a legitimate concern about the procedure being used?

registered voters with unlisted telephone numbers may be underrepresented in the sample