I recommend that you practice using the standard Normal tables to calculate zα/2 and tα/2 .
For this problem, round your answers to 2 digits after the decimal point.
For this problem, round your answers to 3 digits after the decimal point.
For this problem, round your answers to 3 digits after the decimal point.
Suppose that the sample proportion for the U.S. population aged between 25 and 34 years that has a Bachelors’s degree or higher is .34. Further suppose that this estimate came from a survery of 1461 people.
(a) What are the end points of a 90% confidence interval estimate for the population pro- portion? (Round to 2 digits after the decimal place.)
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(b) What are the end points of a 95% confidence interval estimate for the population pro- portion? (Round to 2 digits after the decimal place.)
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(c) What are the end points of a 99% confidence interval estimate for the population pro- portion? (Round to 2 digits after the decimal place.)
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We want to know the mean number of hours worked on a weekend day, among those who work weekends. Suppose that a simple random sample of size 1028 from the target population produced a sample mean of 5.1 hours. Further suppose that the sample standard deviation was 2.2.
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I recommend that you practice using the standard Normal tables to calculate zα/2 and tα/2 ....
1. Costs are rising for all kinds of health care. The mean monthly rent at assisted-living facilities was recently reported to have increased 13% over the last five years. A recent random sample of 116 observations reported a sample mean of $3433. Assume that past studies have informed us that the population standard deviation is $650. For this problem, round your answers to 2 digits after the decimal point. (a) What are the end points of a 90% confidence-interval estimate...
ind tα,df from the following information. [You may find it useful to reference the t table.] tα,df a. α = 0.005 and df = 18 b. α = 0.20 and df = 18 c. α = 0.005 and df = 22 d. α = 0.20 and df = 22 We use the t distribution to construct a confidence interval for the population mean when the underlying population standard deviation is not known. Under the assumption that the population is normally...
Sample Size = 500 Standard Deviation = 10.68981 Sample Mean = 19.51056 a.) What are the end points of a 90% confidence interval for the population mean? (round to 3 digits after Decimal point) b.) What are the end points of a 95% confidence interval fro the population mean? (round to 3 digits after Decimal point)
4. Suppose that 326 of the 666 observations in group 1 have a characterisitic of interest. And, suppose that 255 of the 570 observations in group 2 have this characterisitic. (a) What is the sample proportion for group 1? (round to 5 digits after the decimal place) (b) What is the sample proportion for group 2? (round to 5 digits after the decimal place) (c) What is the difference in the sample proportions between groups 1 and 2? (round to...
1. Find the critical value zα/2 that corresponds to a 94% confidence level. Round your answer to two decimal places. 2. The following confidence interval is obtained for a population proportion, p: 0.273 < p < 0.592. Use these confidence interval limits to find the sample proportion . Round your answer to three decimal places. 0.433 3. Find the minimum sample size : How many commuters must be randomly selected to estimate the mean driving time μ of Chicago commuters?...
A sample of 49 observations is taken from a normal population with a standard deviation of 10. The sample mean is 55. Determine the 99% confidence interval for the population mean. (Round your answers to 2 decimal places.) Confidence interval for the population mean is _______ and _______ .A research firm conducted a survey to determine the mean amount Americans spend on coffee during a week. They found the distribution of weekly spending followed the normal distribution with a population standard deviation...
The following sample data are from a normal population: 14, 12, 16, 19, 17, 15, 10, 9. (a) What is the point estimate of the population mean? (b) What is the point estimate of the population standard deviation? (Round your answer to three decimal places.) (c) With 95% confidence, what is the margin of error for the estimation of the population mean? (Round your answer to one decimal place.) (d) What is the 95% confidence interval for the population mean?...
i need a break down to the simplist level possible In a recent year, the ACT scores on the math portion were distributed normal poslation mean of 21.1 and a population standard deviation of 53. Find the pro randomly selected student has a score between 19 and 24 7 The time spent waiting for a kidney transplant is distributed normally with mean of 1574 and a standard deviation of 212.5 days. What waiting time represents the first quarte The mean...
The population of Mosquito has an unknown mean lifespan μ with standard deviation σ = 0.55 days. A) A sample of 23 mosquito has a mean lifespan of 6.5 days. Construct a 87 % confidence interval to estimate the mean lifespan μ of the mosquito population. Round to 4 decimal places.) The interval: 6.5 (Round E to 2 decimal places) The interval in traditional format: ( B) For the same sample of 23 mosquito with mean lifespan of 6 5...
A random sample of 175 items is drawn from a population whose standard deviation is known to be σ = 50. The sample mean is x¯x¯ = 920. (a) Construct an interval estimate for μ with 95 percent confidence. (Round your answers to 1 decimal place.) The 95% confidence interval is from to (b) Construct an interval estimate for μ with 95 percent confidence, assuming that σ = 100. (Round your answers to 1 decimal place.) The 95% confidence interval is...