ASSIGNMENT 2 – SOLVE AND WRITE THE CORRECT ANSWERS FROM YOUR COMPUTED VALUES IN THE BLANKS PROVIDED.

Part I.A. Select the correct answer and write the appropriate letter in the space provided. (.25 POINTS FOR EVERY CORRECT ANSWER)

______ 1. Which one of the following measures of dispersion does not divide a set of observations into equal parts?

a. quartiles b. deciles

c. percentiles d. standard deviations

______2. The interquartile range is the difference between:

a. the second and third quartile. b. the second and fourth quartile.

c. the first and third quartile. d. the first and last quartile.

______3. A contingency table :

a. can only be used when there are two levels of each variable.

b. can be used to study the relationship between ordinal or nominal level variables.

c. can only be used with interval or ratio level variables.

d. is constructed from the quartiles of a data set..

_______4.A dot plot shows the range of values along the:

a. vertical axis. b. ( x, y ) diagonal axis.

c. median axis. d. horizontal axis.

______ 5. When displaying data with a dot plot, we:

a. do not lose the identity of an individual data point b. are able to show the range of the values.

c. are able to see the shape of the distribution. d. all of those in a, b. c are correct.

______ 6. A scatter diagram is a graphic tool used to portray:

a. the mean of the data values. b. the range of the data values.

c. the midpoint of data values. d. the relationship between variables.

______ 7. In a stem and leaf display:

a. the leaf is the leading digit or digits of the number.

b. the stem is the leading digit or digits of the number.

c. the stem or the leaf can be the leading digit or digits of the number.

d. the stem is the trailing digit.

______ 8. The coefficient of skewness is a measure:

a. of the relationship of the mode and median. b. based on the mean deviation.

c. of the symmetry of a distribution. d. based on the middle 50 percent of the observations.

______9. A box plot is based on:

a. the mean. b. percentiles.

c. deciles. d. the first and third quartile, the median, the maximum and the minimum.

______ 10. The interquartile range is based on:

a. the median. b. the mean deviation.

c. the square of the mean deviation. d. the middle 50 percent of the observations.

Part I.B. Solve the following items and write the correct answers on the spaces provided. (.25 POINTS FOR EVERY CORRECT ANSWER)

____________ 11.Five children have heights of 138 cm, 135 cm, 140 cm, 139 cm and 141 cm. What is the

range of their heights?

____________ 12.What is the range of the following numbers:19, 21, 18, 17, 18, 22, 46?

____________ 13. What is the median in the following numbers:19, 21, 18, 17, 18, 22, 46?

____________ 14. Waleed took 9 tests in different subjects and got scores of 68, 71, 71,84, 53, 71, 62, 67.

What was Walled’s mode score?

____________ 15. In a set of scores, the value 93 appeared twice, more than any other number. What is the

mode score?

____________ 16. The temperature in degrees Celsius over 4 days in April was 28, 21,19 and 30. What was

the mean temperature?

The weekly salaries of six employees at a restaurant are $180, $220, $98, $180, $140, $200. For these six salaries, find:

_____________17. the median

_____________ 18. the mode

_____________19.A storeowner kept a tally of the sizes of suits purchased in her store. Which measure of central tendency should the storeowner use to describe the average size suit sold?

_____________20. A tally was made of the number of times each color of crayon was used by a kindergarten class. Which measure of central tendency should the teacher use to determine which color is the favorite color of her class?

_____________ 21.The science test grades are posted. The class did very well. All students taking the test scored over 75. Unfortunately, 4 students were absent for the test and the computer listed their scores as 0 until the test is taken. Assuming that no score repeated more times than the 0’s, what measure of central tendency would most likely give the best representation of this data?

A card is chosen at random from a deck of 52 playing cards.

There are 4 Queens and 4 Kings in a deck of playing cards. Using these DATA, answer questions 18.

_____________22. What is the probability it is a Queen or a King?

_____________23.There are 4 Queens and 4 Kings, so the Number of ways it can happen is__.

_____________24.There are 52 cards altogether, so the Total number of outcomes is______

_____________25.The probability the card is either a Queen or a King is___

DESCRIBE HOW A FREQUENCY DISTRIBUTION IS PREPARED:

__________________________________________________________________________________________________

__________________________________________________________________________________________________

Part II Show all of your work. Write the answers in the spaces provided.

76 74 71 78 80 67

80 82 67 88 72 78

85 76 84 82 83 80

72 82 77 79 86 89

69 70 82 86 78 77

1. The scores of a sample of 30 students in one of the subjects of a certain University are shown in the table.

Construct a dot plot for the data.

STEM LEAF

5 6 8

6 1 2 2 4 8

7 0 4 6 6

8 0 4 4 6 6 6 6 6

9 0 2 6

10 0

2. The following stem and leaf plot shows the scores on a recent examination of students in Statistics.

2.a. How many students took the test?

2.b. What were the highest and lowest scores?

2.c. How many students scored 70 or higher?

2.d. What percent of the students scored lower than 70?

15 17 23 26 27 35

72 88 91 98 102

3. The revenues of the top eleven personal computer manufacturers are given (in hundred millions).

3.a. Q1

3.b. Q3

3.c. M

3.a. Compute the first quartile.

3.b. The third quartile.

3.c. Determine the median.

3.d. Draw a box plot for the data.