a. What is the point estimate of the population mean?
10+8+12+16+13+11+6+4 = 80 /8
=10
b. What is the point estimate of the population standard deviation (to 2 decimals)?
(1010)^2, (108)^2, (1012)^2, (1016)^2, (1013)^2, (1011)^2, (106)^2, (104)^2
SUM =106
106/n1
106/7 =15.1428
=15.14
√15.14
=3.89
c. With 95% confidence, what is the margin of error for the estimation of the population mean (to 1
decimal)?
=3.3
d. What is the 95% confidence interval for the population mean (to 1 decimal)?
10
± 2.7 = 6.7 to 13.3
=6.7 to 13.3
7)
Sales personnel for Skillings Distributors submit weekly reports listing the customer contacts made
during the week. A sample of 55 weekly reports showed a sample mean of 17.5 customer contacts per
week. The sample standard deviation was 5.6. Provide 90% and 95% confidence intervals for the
population mean number of weekly customer contacts for the sales personnel.
90% Confidence, to 2 decimals:
( , )
17.5
± 1.669 * (5.6/
√55)
17.5
±
1.26 = (16.24 , 18.76)
= (16.24 , 18.76)
95% Confidence, to 2 decimals:
17.5
± 1.998 * (5.6 /
√55)
17.5
± 1.51 =(15.99 , 19.01)
=(15.99 , 19.01)
MAY BE
INCORRECT
8)
The International Air Transport Association surveys business travelers to develop quality ratings for
transatlantic gateway airports. The maximum possible rating is 10. Suppose a simple random sample
of 50 business travelers is selected and each traveler is asked to provide a rating for the Miami
International Airport. The ratings obtained from the sample of 50 business travelers follow.
Mean
6.34
Standard Error
0.305874457
Median
6.5
Mode
8
Standard Deviation
2.16285903
Sample Variance
4.677959184
Kurtosis

1.180629819
Skewness

0.144492246
Range
8
Minimum
2
Maximum
10
Sum
317
Count
50
Confidence
Level(95.0%)
0.614677735
=(6.03,6.65)
9)
The average cost per night of a hotel room in New York City is $269 (
SmartMoney
, March 2009).
Assume this estimate is based on a sample of 45 hotels and that the sample standard deviation is $65.
a.
With 95% confidence, what is the margin of error? Round your answer to the nearest dollar.
$
65 / √45 =9.6896 * 1.998
=19.36 I guess round up??
=20
b.
What is the 95% confidence interval estimate of the population mean? Round your answers to the
nearest dollar.
296
± 20 = (249, 289)
=249 to 289
c.
Two years ago the average cost of a hotel room in New York City was $229. Discuss the change in
10)
Consumption of alcoholic beverages by young women of drinking age in the United Kingdom, the
United States, and Europe was reported (
The Wall Street Journal
, February 15, 2006). Data (annual
consumption in liters) consistent with the findings reported in
The Wall Street Journal
article are shown
for a sample of 20 European young women.
Click on the webfile logo to reference the data.
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 Fall '14
 Statistics, SOLUTIONS, Normal Distribution, Standard Deviation, Homework, Answers , Chapter8, Cengage, GBS, Business Stat