Statistics Assignment

ASSIGNMENT NO. 6

1. A national study of a small sample of street-level drug dealers found that their average income from selling drugs was $52,000 a year. The average starting salary at UNLV for being a college professor is $48,000 a year. Should I encourage my kids or you to become drug dealers rather than college professors based on these income differences?

Answer: No, I wont encourage my kids to become drug dealers. the given ernings for drug dealers is just an average, one can earn less or more. Also the given figure for college professors is the starting salary average, meaning that the average for a college professor is higher than the average of drug dealers.

2. For the following homicide rates per 100,000 population for the following 10 U.S. cities: 26.9, 29.3, 20.5, 25.6, 30.7, 1.7, 25.6, 30.9, 22.4, 31.3. the homicide rates that cover the intermediate range that is between the 20th and 80th percentile rank are between d. 25.6 and 26.9

3. For  homicide rates per 100,000 population for 9 U.S. cities of: 26.9, 29.3, 27.4, 20.5, 25.6, 30.7, 1.7, 25.6, 22.4, the population variance is c. 67.4

4. If the homicide rates per 100,000 population for the following 9 U.S. cities are : 26.9, 29.3, 27.4, 20.5, 25.6, 30.7, 1.7, 25.6, 22.4, the population standard deviation for the homicide rates in these is a. 8.2

5. When an outlier (i.e., an extreme score(s)) is eliminated from a set of scores, b. Eliminating the outlier will decrease the size of the variance.

6. So far, has this class been more, less, or about as difficult as you expected

The most suitable answer for this question is C. this class has been just as difficult/easy as I thought it would be

CLASS EXAM NO. 2

1. When creating a grouped distribution, which of the following should be avoided?
the answer is d. All of the above since

2. If an age distribution is grouped into intervals of <21, 21-34, 35-39, 40-44, 45-49, 50-59, 60-74, and > 74, it should be treated as a(n):

The answer is d. none of the above are true

3. Your grade point average is an example of a weighted mean. The answer is b. False

4. Medians and means are appropriate measures of central tendency for nominal, ordinal, and interval/ratio measures. The answer is b. false.

5. A professor found that all of the students in her class were registered for 15 semester hours of classes. This would mean that: d. all of the above are true.
(the interquatile range, mean and standard deviation are equal to zero)

6. What is the mean for the following 5 scores: 11, 51, 41, 31, 21. Ans is c. 31

7. What is the median for the following 5 scores: 1, 5, 4, 3, 2? Ans is c. 3

8. What is the mode for the following 5 scores: 11, 15, 14, 12, 12? Ans is b. 12

9. What is the population variance for the following 5 scores: 10, 50, 40, 20, 30? Ans is b. 200

10. What is the population standard deviation for the following 5 scores: 6, 10, 9, 7, 8? Ans is b. 1.41

11. In a bar graph: d. all of the above since bars should be of equal width, the vertical axis should usually begin at zero if possible and values of ordinal variables should usually be listed from lowest on the left to highest on the right.

12. Which of the following set of categories is not collectively exhaustive? Ans is d. all of the above.

13. If a variable's mode, median, and mean are all the same value, we know that the distribution of the variable is: a. normal or bell shaped.

14. Which of the following is appropriate to describe any variable regardless of its level of measurement: Ans se. None of the above.

15. For the given table where judges opinion towards mandatory sentencing are:like it very much (26.4%),like it somewhat (44.8%),dislike it somewhat (15.3%), dislike very much (13.5%) and with a sample size (n) of 1553, the true statement is b. These percentages could be displayed with a bar graph

16. A team of researchers observed the behavior of 20 children during breaktime on a school playground. The observer recorded how many times each child performed a "violent act"-- be it a push, a kick, or a punch--against another child. The scores of the 20 children were as follows: 2 0 1 0 0 4 0 0 100 2 1 0 3 0 1 0 11 0 0 2. Based on this data, b. half of these kids performed a violent act.

17. A review of the records of 20 male and 20 female adjudicated delinquents revealed the following numbers of prior arrests for violent crimes:
males: 0 2 1 7 4 2 2 1 6 5 0 0 1 2 4 1 0 0 2 9
females: 0 0 1 4 2 3 1 1 5 1 0 0 0 1 0 3 2 1 0 0.
based on the data, b. the standard deviation of the number of prior arrests for violent crimes is larger for males than females.

18. A team of researchers observed the behavior of 20 children during breaktime on a school playground. The observer recorded how many times each child performed a "violent act"-- be it a push, a kick, or a punch--against another child. The scores of the 20 children were as follows: 2 0 1 0 0 4 0 0 100 2 1 0 3 0 1 0 11 0 0 2. Which of the following statements are true based on this data? Ans  b. 35% of the kids committed 2 or more violent acts.

19. A review of the records of 20 male and 20 female adjudicated delinquents revealed the following numbers of prior arrests for violent crimes:
males: 0 2 1 7 4 2 2 1 6 5 0 0 1 2 4 1 0 0 2 9
females: 0 0 1 4 2 3 1 1 5 1 0 0 0 1 0 3 2 1 0 1. From the data, a. The clear majority of both male and female delinquents have a prior arrest for violent crimes.

20. For tha data in Que 19 above, these two statements are true: c. the modal number of prior arrests is 0 for both males and females. And b. the modal number of prior arrests for violent crimes is higher for females than males.