1. Lunch break: In a recent survey of working Americans ages 25-34 , the average weekly amount spent on lunch was $43.26 with standard deviation $3.04. The weekly amounts are approximately bell-shaped.

Estimate the percentage of amounts that are between $ 37.18 and $49.34.

Estimate the percentage of amounts that are between $34.14 and $52.38

2. The following TI-84 Plus display presents some sample statistics.

	1-Var-Stats
	x =69
	x=2291
	x2 =182,361
	Sx=5
	x=5.12989176
	n=29

a. Assume that a histogram of the sample is bell-shaped. Approximately what percentage of the sample values are between 64 and 74?

b. Assume that a histogram for the sample is bell-shaped. Between what two values will approximately 95% of the sample be?

c. If we do not assume that the histogram is bell-shaped, at least what percentage of the sample values will be between 59 and 79?

3. Lunch break: In a recent survey of 624 working Americans ages25-34, the average weekly amount spent on lunch as $43.99 with standard deviation $3.05. The weekly amounts are approximately bell-shaped.

(a) Estimate the percentage of amounts that were less than $40.94.Round the answer to one decimal place.

(b) Estimate the percentage of amounts that were greater than $50.09.Round the answer to one decimal place.

(c) Estimate the percentage of amounts that were between $43.99and $47.04.Round the answer to one decimal place.

4. Price of electricity: The Energy Information Administration records the price of electricity in the United States each month. In July 2013, the average price of electricity was 12.65 cents per kilowatt-hour. Suppose that the standard deviation is 2.90 cents per kilowatt-hour. What can you determine about these data by using Chebyshev's Inequality with =K3?

At least % of the data fall between and cents per kilowatt-hour. (Round answers to two decimal places as necessary.)

10. Stock prices: Following are closing prices for a certain stock during June and July of a certain year.

June
485.52	484.78	474.02	487.01	488.50
483.19	497.99	488.56	486.25	482.05
472.68	472.08	454.26	444.95	482.37

July
450.07	450.20	456.56	467.49	475.83
489.20	491.34	494.02	459.61	466.18
481.59	477.50	484.81	490.06	488.97

(a) Find the population standard deviation and variance for the prices in June. Round the answers to at least three decimal places.

The population standard deviation for the prices in June is. The population variance for the prices in June is.

(b) Find the population standard deviation and variance for the prices in July. Round the answers to at least three decimal places.

The population standard deviation for the prices in July is. The population variance for the prices in July is.

15. Hazardous waste:Following is a list of the number of hazardous waste sites in a sample of states of the United States in a recent year. The list has been sorted into numerical order.

1	9	9	11	12	12	12	13	14	15
15	16	19	19	20	21	25	26	29	30
32	32	32	38	40	48	49	52	67	116

Source: U.S. Environmental Protection Agency

Part 1 of 4

(a) Find the first and third quartiles of these data.

The first quartile of these data is . The third quartile of these data is .

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