Question 138036: Hi, I need some help with these few problems. Thanks,
1. Suppose 1,600 of 2,000 registered voters sampled said they planned to vote for the Republican candidate for president. Using the 0.95 degree of confidence, what is the interval estimate for the population proportion (to the nearest tenth of a percent)?
A) 78.2% to 81.8%
B) 69.2% to 86.4%
C) 76.5% to 83.5%
D) 77.7% to 82.3%
E) None of the above
2. A market survey was conducted to estimate the proportion of homemakers who could recognize the brand name of a cleanser based on the shape and color of the container. Of the 1,400 homemakers, 420 were able to identify the brand name. Using the 0.99 degree of confidence, the population proportion lies within what interval?
A) 0.250 and 0.350
B) 0.100 and 0.400
C) 0.950 and 0.997
D) 0.268 and 0.332
E) None of the above
3. The mean weight of trucks traveling on a particular section of I-475 is not known. A state highway inspector needs an estimate of the mean. He selects a random sample of 49 trucks passing the weighing station and finds the mean is 15.8 tons, with a standard deviation of the sample of 3.8 tons. What is the 95 percent interval for the population mean?
A) 14.7 and 16.9
B) 13.2 and 17.6
C) 10.0 and 20.0
D) 16.1 and 18.1
E) None of the above
4. Mileage tests were conducted on a randomly selected sample of 100 newly developed automobile tires. The mean tread wear was found to be 50,000 miles with a standard deviation of 3,500 miles. What is the best estimate of the mean tread life in miles for the entire population of these tires?
A) 50,000
B) 3,500
C) (50,000/100)
D) (3,500/100)
E) None of the above
5. For a given confidence interval, what is the interpretation of a 96% confidence level?
A) 96% chance that the given interval includes the true value of the population parameter
B) Approximately 96 out of 100 such intervals would include the true value of the population parameter
C) 4% chance that the given interval does not include the true value of the population parameter
D) Both "a" and "c" are true
E) None of the above is correct
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! 1. Suppose 1,600 of 2,000 registered voters sampled said they planned to vote for the Republican candidate for president. Using the 0.95 degree of confidence, what is the interval estimate for the population proportion (to the nearest tenth of a percent)?
I ran a 1-Prop ZInt on my TI to get: 0.782 to 0.817
A) 78.2% to 81.8%
B) 69.2% to 86.4%
C) 76.5% to 83.5%
D) 77.7% to 82.3%
E) None of the above
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2. A market survey was conducted to estimate the proportion of homemakers who could recognize the brand name of a cleanser based on the shape and color of the container. Of the 1,400 homemakers, 420 were able to identify the brand name. Using the 0.99 degree of confidence, the population proportion lies within what interval?
I ran a 1-Prop ZInt test on my TI calculato to get 0.27985 , 32015
A) 0.250 and 0.350
B) 0.100 and 0.400
C) 0.950 and 0.997
D) 0.268 and 0.332
E) None of the above
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3. The mean weight of trucks traveling on a particular section of I-475 is not known. A state highway inspector needs an estimate of the mean. He selects a random sample of 49 trucks passing the weighing station and finds the mean is 15.8 tons, with a standard deviation of the sample of 3.8 tons. What is the 95 percent interval for the population mean?
I ran a TInterval Test on my TI calculator to get the "A" answer
A) 14.7 and 16.9
B) 13.2 and 17.6
C) 10.0 and 20.0
D) 16.1 and 18.1
E) None of the above
-----------------------------
4. Mileage tests were conducted on a randomly selected sample of 100 newly developed automobile tires. The mean tread wear was found to be 50,000 miles with a standard deviation of 3,500 miles. What is the best estimate of the mean tread life in miles for the entire population of these tires?
The point estimate answer is 50,000 miles
A) 50,000
B) 3,500
C) (50,000/100)
D) (3,500/100)
E) None of the above
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5. For a given confidence interval, what is the interpretation of a 96% confidence level?
A) 96% chance that the given interval includes the true value of the population parameter
B) Approximately 96 out of 100 such intervals would include the true value of the population parameter
C) 4% chance that the given interval does not include the true value of the population parameter
D) Both "a" and "c" are true
E) None of the above is correct
Depending on your textbook, B might be the answer. A and C and D are
definately wrong. E might also be the answer.
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Cheers,
Stan H.
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