MATH 1340 Statistics Chapter 1 Homework Questions

38. Find the data value with a z-score of 2.3 that comes from a population with mean of μ = 10 and standard deviation of σ = 1.4.

c. 13.22

16. Identify the smallest value in the data set represented by the following stemplot. Stem: 2, 3, 4. Leaves: 15, 09, 26.

c. 21

20. Refer to the frequency distribution from Section 1.2 Exercise #2 in the text. What is the lower class boundary for the class "30-39?"

c. 29.5

29. Find the mean of the following sample data set:{75, 65, 100, 80, 85, 75, 100}

c. 82.9

22. Use the empirical rule to answer the following question.The heights of American men have an approximately bell-shaped distribution with a mean of 70 inches (5' 10") and standard deviation of 3 inches. What is the percentage of American men whose height is between 61 and 79 inches (5' 1" and 6' 7")?

c. 99.7%

33. Refer to the boxplot given in Section 1.4 Exercise 22 of the text. Describe the distribution of the data.

c. approximately symmetric

9. Identify the highest level of measurement that is appropriate:Temperature of water in a river, measured in degrees Celsius

c. interval

5. Identify the type of study: A study is designed to determine if there is a link between smoking and glaucoma. Records from past glaucoma patients of several ophthalmologists are obtained. These patients are divided into smokers and non-smokers.

c. observational; retrospective

7. Identify a reason why we should be skeptical of any claim or statistical evidence involving the following: An advertisement for A-1 Motor Oil states that in a survey of auto mechanics across the country, the majority of them use A-1 Motor Oil in their own vehicles.

c. self-interest survey

28. Find the standard deviation of the following sample data set:{75, 65, 100, 80, 85, 75, 100}

d. 13.2

25. Refer to the frequency distribution table given in Section 1.3 Exercise 12 of the text. What is the mean of this sample data?

d. 19.8

36. Find the value that would be in the 15th percentile for the following data set:{6, 10, 7, 2, 9, 8, 7, 3, 5}

d. 3

30. Find the IQR for the following data set. {18, 15, 16, 22, 24, 12, 17, 25, 16, 19, 20, 17}

d. 5

8. Identify a reason why we should be skeptical of any claim or statistical evidence involving the following: A study shows that during the early 20th century, a strong correlation existed between the number of people who owned radios and the number of people put into insane asylums. Therefore, people who owned a radio were more likely to be declared insane and put into an insane asylum.

d. correlation does not imply causality

11. Identify the highest level of measurement that is appropriate:The volume of a ball bearing that has just been manufactured

d. ratio

17. Refer to the frequency distribution from Section 1.2 Exercise #2 in the text. Sketch a histogram for this data, and use it to determine which of the following is the best description of the distribution.

d. skewed right

6. Identify the type of study: A study is designed to determine the current average number of alcoholic beverages consumed weekly by residents of a particular region. A survey of 273 residents is conducted.

b. observational; cross-sectional

10. Identify the highest level of measurement that is appropriate: Fire danger level posted by the Forest Service (low, moderate, high, or extreme)

b. ordinal

1. Identify whether the given value is a statistic or parameter: It was determined that 52% of all registered voters in Oakland County are female.

b. parameter

15. Identify whether the given data is quantitative or qualitative:The course numbers (e.g. 101, 1340, 2760) of the math classes offered by your college

b. qualitative

23. Use the "range divided by 4" rule to approximate the standard deviation for the given set of sample data.{3, 5, 4, 1, 2, 6}

c. 1.25

19. Refer to the frequency distribution from Section 1.2 Exercise #2 in the text. What is the class width?

c. 10

26. Refer to the histogram in Section 1.3 Exercise 10 from the text. Find the mode of the data that is given in this histogram.

c. 10-14 and 20-24

35. Find the 5-number summary for the following data set. {18, 15, 16, 22, 24, 12, 17, 25, 16, 19, 20, 17}

c. 12, 16, 17.5, 21, 25

31. Refer to the boxplot given in Section 1.4 Exercise 22 of the text. What are the cut-off values for outliers using the 1.5×IQR rule?

a. 1 and 9

18. Refer to the frequency distribution from Section 1.2 Exercise #2 in the text. What is the class midpoint for the class "30-39?"

a. 34.5

34. Find the percentile of the data value 7 in the following data set:{6, 10, 7, 2, 9, 8, 7, 3, 5}

a. 44th percentile

21. Find the "usual" minimum and maximum values in a data set that has the same mean and standard deviation as the following data set.{75, 65, 100, 80, 85, 75, 100}

a. 56.5 and 109.2

27. Find the median of the following sample data set:{75, 65, 100, 80, 85, 75, 100}

a. 80

12. Identify whether the given data is discrete or continuous:The number of apples in a tree

a. discrete

14. Identify whether the given data is quantitative or qualitative:The weight of a package to be sent via overnight mail

a. quantitative

3. Identify the type of sampling that is used: A list of all registered voters in a state is given to a researcher who would like to determine if a particular candidate is likely to be elected. The researcher has a computer randomly generate several hundred numbers, and those numbers are used to select names from the list to form a sample.

a. random

2. Identify whether the given value is a statistic or parameter:In a random sample of U.S. households, it was found that 72% have high-speed Internet.

a. statistic

24. Refer to the frequency distribution table given in Section 1.3 Exercise 12 of the text. What is the standard deviation of this sample data?

b. 11.0

37. Find the z-score for a value of 30 if it comes from a sample with mean of = 20 and standard deviation of s = 3.5.

b. 2.86

32. Refer to the information given in Section 1.4 Exercises 23-24 of the text. Compute the z-scores for Marty (98, Ms. Cooper's class) and Lisa (96, Miss Hoover's class), and identify which one did relatively better on his/her test.

b. Marty: z ≈ 1.07; Lisa: z ≈ 1.15; Lisa did relatively better

13. Identify whether the given data is discrete or continuous:The number of ounces that a water bottle can hold

b. continuous

4. Identify the type of sampling that is used: You are researching the proportion of college students who are required to take Statistics for their majors. You survey all of the students in all of the classes that you are taking this semester.

b. convenience