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1. One study about smokeless tobacco used40 university students as subjects. Twenty were given smokeless tobacco to chew and twenty were given a substance that looked and tasted like smokeless tobacco. The students were randomly assigned to one of the groups. The students’ blood pressure and heart rates were measured before they started chewing and again 20 minutes after they had been chewing. A significant increase in heart rate occurred in the group that chewed smokeless tobacco.

a. Is this an experiment or an observation?

b. If it’s an experiment, what is the response or dependent variable? If it’s an observation, what are they observing?

c. Which group serves as the control group?

d. Could the students’ blood pressure be affected by the knowledge that they are part of a study?

e. Do you think this is a good way to study the effect of smokeless tobacco? Why or why not?

2. Determine if the variables listed below are qualitative or quantitative. If the variable is quantitative, determine if it is discrete or continuous.

a. times it takes to mow a lawn

b. Classification of children at a daycare(infant, toddler, preschool)

c. Phone number

d. Number of cheeseburgers sold in a day on a college campus

3. Following the 2010 national midterm elections, 12% of the governors of the 50 United States were female. Is 12% a parameter or a statistic and why?

4. A survey asked if people would like to spend the rest of their careers with their present employers. The results are shown.:

Response	Number of People
Yes	660
No	260
Undecided	80

a. Construct a relative frequency distribution. You may add a column to this table.

b. Construct a pie chart.

c. Construct a bar chart.

5. The number of highway miles per gallon of the 10 worst vehicles is shown below:

12 15 13 14 15 16 17 16 17 18

Find the mean, median, mode, range, variance, and IQR

6. You set up a survey on how people believe the American culture (television, movies, magazines, and popular music) influences illegal drug use. Your survey consists of 2250 adults and adolescents from around the United States. A consumer group petitions you for more information about your survey. Since you designed this study, answer the following questions for them:

a. What type of survey did you use and why? (phone, mail, or interview)

b. What are the advantages and disadvantages of the survey methods you did not use?

c. What data did you collect in your survey? Why did you choose it?

d. What type of scale (nominal, ordinal, interval, or ratio) did you use? Why?

e. Which of the methods (stratified, systematic, cluster, or convenience) did you use and why?

7. For the month of June in the city of Chicago, 37% of the days are cloudy. Also in the same month and city, 21% of the days are cloudy and rainy. What is the probability that a randomly selected day in June in Chicago will be rainy if we already know it is cloudy?

8. The following is a sample of 19 December utility bills (in dollars) from a neighborhood. What is the largest bill in the sample that would not be considered an outlier?

52, 62, 66, 68, 72, 74, 76, 76, 76, 78, 78, 82, 84, 84, 86, 88, 92, 96, 110

9. If one card is drawn from a standard 52 card playing deck, determine the probability of getting a jack or a four or a heart or a spade. Leave as a fraction or round to the nearest hundredth.

10. A person wins in a gambling game if he gets exactly 2 heads in 5 flips of a biased coin. The probability of getting a head is 0.7. a) Find the probability that he wins. Should he play? b) If the rules change and he wins if he gets at least 4 heads in 5 flips, what is the probability that he wins?

11. There is a probability of 0.04 that a lamp purchased at a given store doesn’t work. A person purchases 3 lamps. a) Define a random variable as the number of non-working lamps. What is the sample space? b) Find the probability distribution.

12. The tread life of a particular brand of tire is a random variable described by a normal distribution with a mean of 65,000 miles and a standard deviation of 2500 miles. What is the probability a particular tire of this brand will last more than 57,400 miles? What percentage of tires will last between 50,000 miles and 70,000 miles?

13. The amount of corn chips dispensed into a 13-ounce bag by the dispensing machine has been identified as possessing a normal distribution with a mean of 13.5 ounces and a standard deviation of 0.1 ounce. Suppose 100 bags of chips were randomly selected from this dispensing machine. Find the probability that the sample mean weight of these 100 bags exceeded 13.55 ounces.

14. A marketing research company needs to estimate which of two medical plans its employees prefer. A random sample of n employees produced the following 95% confidence interval for the proportion of employees who prefer plan A. (0.299, 0.539) What is the point estimate of the true proportion of employees who prefer that plan? What is the margin of error?

15. The following small data set represents a simple random sample from a population whose mean is 50.

43	63	53	50	58	44
53	53	52	41	50	43

a. A normal probability plot indicates that the data could come from a population that is normally distributed with no outliers. Find a 95% confidence interval for this data set.

b. Suppose the observation, 41, is mistakenly entered as 14. Show that this observation is an outlier.

c. Find a 95% confidence interval with the data set containing the outlier. What effect does the outlier have on the confidence interval?