Week 9 Homework: Statistics (Homework) Consider the line graph shown in the figure. (a) During which month did Herb incur the most expenses? 1 (b) During which month did Lisa incur the least expenses?...

Week 9 Homework: Statistics (Homework)

1. Consider the line graph shown in the figure.

(a) During which month did Herb incur the most expenses?
1
(b) During which month did Lisa incur the least expenses?
2








2 The amount of electricity used in a typical all-electric home is shown in the circle graph in the figure. If, in a certain month, a home used 1,200 kwh (kilowatt-hours), find the amounts of electricity used from the graph.


(a) The amount of electricity used by the water heater
1 kwh
(b) The amount of electricity used by the stove
2 kwh
(c) The amount of electricity used by the refrigerator
3 kwh
(d) The amount of electricity used by the clothes dryer
4 kwh

3.

Consider the scatter diagram as shown in the figure. For states with income from crops less than a billion dollars, the number of states with income from livestock less than a billion dollars is about which of the following?
10 18 21 14




4. Suppose that you weigh 101 pounds and have two drinks in 2 hours. According to the figure, are you seldom illegal, maybe illegal, or definitely illegal?
seldom illegal maybe illegal definitely illegal








5. Consider the following data set.
The heights (rounded to the nearest inch) of 30 students are given.

66	68	65	70	67	67	68	64	64	66
64	70	72	71	69	64	63	70	71	63
68	67	67	65	69	65	67	66	69	69

Make a frequency distribution for the data set.

Height	Frequency
63	1
64	2
65	3
66	4
67	5
68	6
69	7
70	8
71	9
72	10

6. A newspaper article discussing whether Social Security could be cut offered the information shown in the figure. Use the information in these graphs to answer the question. What is the difference between the amount of money collected from Social Security taxes and the amount paid out in 1992?
$50 billion $20 billion $150 billion $100 billion $10 billion













7. A newspaper article discussing whether Social Security could be cut offered the information shown in the figure. Use the information in these graphs to answer the question. How many workers pay into Social Security for each person getting benefits in 2000?
1 persons











8. Find the three measures of central tendency.


(a) Find the mean.
1
(b) Find the median.
2
(c) Find the mode. (If there is no mode, enter NONE in the answer box.)
3









9. Find the range and the variance (correct to one decimal place).


(a) Find the range.
1
(b) Find the variance.
2







10. The 2001 monthly cost for health care for an employee and two dependents is given in the following table. Select a box plot for the monthly costs of health care (ranked from lowest to highest).

Provider	Cost
Maxicare	$415.24
Cigna	$424.77
Health Net	$427.48
Pacific Care	$428.05
Redwoods Plan	$431.52
Kaiser	$433.50
Aetna	$436.11
Blue Shield	$442.28
Omni Healthcare	$457.86
Lifeguard	$457.94

Q
₁
= $427.48,
Q
₂
= $432.50,
Q
₃
= $442.28
Q
₁
= $427.48,
Q
₂
= $432.51,
Q
₃
= $442.28
Q
₁
= $427.48,
Q
₂
= $433.50,
Q
₃
= $457.86
Q
₁
= $427.48,
Q
₂
= $432.52,
Q
₃
= $442.28
Q
₁
= $424.77,
Q
₂
= $431.52,
Q
₃
= $442.28








11. A class obtained the following scores on a test. Find the mean, the median, the mode, and the range for the class.

Test Score	Frequency
90	2
80	5
70	10
60	4
50	2
40	2

(a) Find the mean.
1
(b) Find the median.
2
(c) Find the mode.
3
(d) Find the range.
4







12. The graph in the figure shows the distribution of scores on an examination. Which of the following statements is true about the distribution?


The median is greater than the mode. The mean is the same as the mode. The mean is less than the mode. The median is the same as the mode.








13. Use the nutritional information about candy bars given in the table to answer the questions.


(a) What is the mean calories from fat? (Round the answer to the nearest hundredth.)
1 calories
(b) What is the median (in grams) of total fat?
2 g
(c) What is the mode (in grams) of the serving size?
3 g










14. The number of bedrooms of homes in a certain community is shown on the table below.
(a) Find the cumulative distribution for the table.

Number of Bedrooms	Percent	Cumulative
0	2%	1 %
1	8%	2 %
2	24%	3 %
3	35%	4 %
4	21%	5 %
5	7%	6 %
6 or more	3%	7 %

(b) Find the mean for the table. (Give the answer to two decimal places.)
8
(c) Find median for the table.
9
(d) Find mode for the table.
10







15. Consider the following table.


For a particular value, this table gives the percent of scores between the mean and the z-value of a normally distributed random variable. What percent of the total population is found between the mean and the
z-score, assume
z
= 2.93.
1







16. Suppose that people's heights (in centimeters) are normally distributed, with a mean of 175 and a standard deviation of 6. We find the heights of 40 people.
(a) How many would you expect to be between 169 and 181 cm tall?
1
(b) How many would you expect to be taller than 170 cm?
2







17. The diameter of an electric cable is normally distributed, with a mean of 0.8 inch and a standard deviation of 0.01 inch. What is the probability that the diameter will exceed 0.825 inch? (Give the answer to four decimal places.)
1









18. The breaking strength (in pounds) of a certain new synthetic is normally distributed, with a mean of 166 and a variance of 4. The material is considered defective if the breaking strength is less than 162 pounds. What is the probability that a single, randomly selected piece of material will be defective? (Give the answer to two decimal places.)
1 %