Question

You may need to use the appropriate appendix table or technology to answer this question. A production process is checked periodically by a quality control inspector. The inspector selects simple random samples of 40 finished products and computes the sample mean product weights x. If test results over a long period of time show that 5% of the x values are over 2.1 pounds and 5% are under 1.9 pounds, what are the mean and the standard deviation (in lb) for the population of products produced with this process? (Round your answer for the standard deviation to two decimal places.)

mean lb

standard deviation lb

Answer #1

A production process is checked periodically by a quality
control inspector. The inspector selects simple random samples of
90 finished production and computes the sample mean product weights
bar. If results over a long period of time show that 5% of bar
values are more than 8.5 pounds and 5% are less than 7.5 pounds,
what are the mean and standard deviation for the population of
production produced within the process? It may help to sketch the
standard normal curve.

You may need to use the appropriate appendix table or technology
to answer this question. A population has a mean of 200 and a
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(a) What is the probability that the sample mean will be within
±5 of the population mean?
(b) What is the probability that the sample mean will be within
±10...

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Barron's reported that the average number of weeks an
individual is unemployed is 18.5 weeks. Assume that for the
population of all unemployed individuals the population mean length
of unemployment is 18.5 weeks and that the population standard
deviation is 4 weeks. Suppose you would like to select a sample of
60 unemployed individuals for a follow-up study.
(a) Show the sampling distribution of x,...

You may need to use the appropriate appendix table or technology
to answer this question.
The Economic Policy Institute periodically issues reports on
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level wages for male college graduates were $21.68 per hour and for
female college graduates were $18.80 per hour in 2011.† Assume the
standard deviation for male graduates is $2.30, and for female
graduates it is $2.05. (Round your answers to four decimal
places.)
(a)
What is...

You may need to use the appropriate appendix table or technology
to answer this question.
A simple random sample with
n = 59
provided a sample mean of 26.5 and a sample standard deviation
of 4.4. (Round your answers to one decimal place.)
(a)
Develop a 90% confidence interval for the population mean.
to
(b)
Develop a 95% confidence interval for the population mean.
to
(c)
Develop a 99% confidence interval for the population mean.
to
(d)
What happens to...

You may need to use the appropriate appendix table or technology
to answer this question. An 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 a certain airport. The
ratings obtained from the sample of 50 business travelers
follow.
6 4 6 8 7 7 6 3 3...

You may need to use the appropriate appendix table or technology
to answer this question. Software companies work hard to produce
software that does not have bugs in it. The average number of bugs
found in a new software program at its inception is 26.5 with a
standard deviation of 3.5 bugs. A random sample of size 45 software
programs was examined. (a) Determine the mean (in bugs) of the
sampling distribution of the sample mean for samples of size...

You may need to use the appropriate appendix table or technology
to answer this question.
A newspaper reports that the average expenditure on Valentine's
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consumers was $138.67, and the average expenditure in a sample
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to answer this question.
A newspaper reports that the average expenditure on Valentine's
Day is $100.89. Do male and female consumers differ in the amounts
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consumers was $137.67, and the average expenditure in a sample
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You may need to use the appropriate appendix table or technology
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A random sample of 49 SAT scores of students applying for merit
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95% confidence.
A. 2.011
B. 8.617
C. 50.317
D. 60.319

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