Test #1

1. A baseball player has a batting average of 0.325 each week of the season, with a standard deviation of 0.065. What was the z score when he bats 0.410 one week?

1.308

3. What are the boundaries of the class 1.87-3.43?

1.865-3.435

24. The costs per load (in cents) of 39 dish-washing detergents tested by a consumer organization are shown here. Find the standard deviation of the sample. Class Limits Frequency 20-28 12 29-37 11 38-46 4 47-55 12

11.1

25. Given that the mean of a set of data is 25 and the standard deviation is 3, what is the coefficient of the variation?

12%

19. The average weight of adult male bison in a wildlife preserve is 1700 pounds with a standard deviation of 280 pounds. Find the weight of an adult bull whose z-score is 0.5.

1840 lb

4. A random sample of 30 malls shows the number of stores each one contains. Find the mean and modal class. Class Boundaries Frequency 11-15 6 16-20 3 21-25 6 26-30 10 31-35 5

23.8; 26-30

16. The average weekly earnings in dollars for various industries are listed below. Find the percentile rank of 609. 728, 609, 547, 636, 586, 678, 784, 500, 836, 861

35th

12. Identify the five-number summary of the following data set. 7, 11, 21, 28, 32, 33, 37, 43.

7,16,30,35,43

14. An automobile dealer wants to construct a pie graph to represent types of cars sold in July. He sold 72 cars, 16 of which were convertibles. How many degrees should be used for the convertibles section?

80 degrees

7. The average resident of Metro City produces 670 pounds of solid waste each year, and the standard deviation is approx 75 pounds. Find the weight range that contains at least 75% of all residents' annual garbage weights. Between 445 and 895 pounds Between 370 and 970 pounds Between 520 and 820 pounds Between 595 and 745 pounds

Between 520 and 820 pounds

5. For a given data set, the ogive and the frequency polygon will have the same overall shape. True False

False

10. Questioning every 14th customer leaving a theatre about the movie they had seen, would be an example of systematic sampling. True False

True

2. The frequency polygon is a graph that displays the data by using lines that connect points plotted for the frequencies at the midpoints of the classes.

True

6. Rating a restaurant by a number of stars is an example of an ordinal level of measurement. True False

True

15. The amount of time needed to run the Boston marathon is an example of which type of variable?

continuous

11. An independent variable can also be called a(n)

explanatory variable

22. Based on her electric bills from last year, Mrs. Smith expects that she will be paying $75/month this year. This is an example of descriptive statistics. True False

false

20. The size of the box in a box plot shows the _____________ of the data set.

interquartile range

8. Classifying the fruit in a basket as apple, orange, or banana, is an example of the ________ level of measurement.

nominal

9. A characteristic or measure obtains by using all the data values for a specific population is called a ____________.

parameter

13. What type of sampling is being employed if the country is divided into economic classes and a sample is chosen from each class to be surveyed?

stratified sampling

21. A television station interviews five movie viewers after the first showing of a movie. After finding out that all five enjoyed the movie very much, the reporter states that this movie will definitely be a big hit. This is an example of ___________________. Ambiguous averages Changing the subject Suspect samples Detached statistics

suspect samples

17. The median can be a more appropriate measure of central tendency if the data set contains outliers. True False

true

18. Inferential statistics is based on probability. True False

true

23. Chebyshev's theorem can be used to find the minimum percentage of the values in a data set that will fall within a certain distance of the mean. True False

true