Reaserchers working in a remote area of africa feel that 50% of the families in the...
Reaserchers working in a remote area of africa feel that 50% of the families in the area are without adequate drinking water ethier through contamination or unavailiabilty.
What is the sample size that will be necessary to estimate the percent without adequte drinking water within 3% with 95% confidence?
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Reaserchers working in a remote area of africa feel that 50% of
the families in the...
According to a report by the PEW Research Center, 85% of adults under 30 feel optimistic...
According to a report by the PEW Research Center, 85% of adults under 30 feel optimistic about the economy, but the optimism is shared by only 45% of those who are over 50 (Newsweek, September 13, 2010). A research analyst would like to construct 95% confidence intervals for the proportion patterns in various regions of the country. She uses the reported rates by the PEW Research Center to determine the sample size that would restrict the margin of error to...
8.2.27 Question Help o What sample size is needed to estimate a population mean within 50...
8.2.27 Question Help o What sample size is needed to estimate a population mean within 50 of the true mean value using a confidence level of 95%, if the true population variance is known to be 140,6252 The sample size must be at least (Round up to the nearest whole number)
According to a recent Gallup poll, only 294 out of 1014 adults working full time strongly agree that their performance r...
According to a recent Gallup poll, only 294 out of 1014 adults working full time strongly agree that their performance reviews are fair. A) Based on this finding, what is the best point estimate (in percentage form) for the true estimate of adults working full time that strongly agree that their performance reviews are fair? B) Find the margin of error for this poll assuming 95% confidence (using normal approximation). Carry to four decimal places. C) What is the 95%...
In a sample of n= 11 lichen specimens, the researchers found the mean and standard deviation...
In a sample of n= 11 lichen specimens, the researchers found the mean and standard deviation of the amount of the radioactive element, cesium- 137, that was present to be 0.009 and 0.003 microcurie per milliliter, respectively. Suppose the researchers want to increase the sample size in order to estimate the mean μ to within 0.002 microcurie per milliliter of its true value, using a 95% confidence interval. Complete parts a through c. a. What is the confidence level desired...
8. value: 10.00 points An experiment was conducted to determine the effectiveness of a method designed...
8. value: 10.00 points An experiment was conducted to determine the effectiveness of a method designed to remove oil wastes found in soil. Three contaminated soil samples were treated. After 95 days, the percentage of contamination removed from each soil sample was measured, with a mean of 49.3 percent and a standard deviation of 1.5 percent. If we wished to narrow the boundary around u for a 98 percent confidence interval to within 0.5 percent, how many soil samples should...
(3 points) The Highway Safety Department wants to study the driving habits of individuals. A sample...
(3 points) The Highway Safety Department wants to study the
driving habits of individuals. A sample of 28 cars traveling on a
particular stretch of highway revealed an average speed of 69.9
miles per hour with a standard deviation of 4.2 miles per hour.
Round to 4 decimal places.
1.Calculate a 95% confidence interval for the true mean speed of
all cars on this particular stretch of highway.
( , )
2. What sample size is needed to estimate the...
a through d please People were polled on how many books they read the previous year....
a through d please
People were polled on how many books they read the previous year. Initial survey results indicate that s= 15.3 books. Complete parts (a) through (d) below. Click the icon to view a partial table of critical values. (a) How many subjects are needed to estimate the mean number of books read the previous year within four books with 95% confidence? This 95% confidence level requires subjects. (Round up to the nearest subject) (b) How many subjects...
A survey of 978 online shoppers was conducted In response to the question of what would...
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7. in an area. A sample survey is to be conducted to determine the mean family...
7. in an area. A sample survey is to be conducted to determine the mean family income The question is, how many families should be sampled? In order to get more information about the area, a small pilot survey was conducted, and the standard deviation dollars. of the sample was conducted to be five hundred Ine spoOnsor of the survey wants you to use the ninety-nine percent confidence coefficient. Further, if you find the sample mean family income to be...
3. An IQ test is designed so that the mean is 100 and the standard deviation is 19 for the population of adults. Find t...
3. An IQ test is designed so that the mean is 100 and the standard deviation is 19 for the population of adults. Find the sample size necessary to estimate the mean IQ score of nurses such that it can be said with 99 % confidence that the sample mean is within 5 IQ points of the true mean. Assume that o = 19 and determine the required sample size using technology. The required sample size is _ (Round up...
According to a report by the PEW Research Center, 85% of adults under 30 feel optimistic about the economy, but the optimism is shared by only 45% of those who are over 50 (Newsweek, September 13, 2010). A research analyst would like to construct 95% confidence intervals for the proportion patterns in various regions of the country. She uses the reported rates by the PEW Research Center to determine the sample size that would restrict the margin of error to...
8.2.27 Question Help o What sample size is needed to estimate a population mean within 50 of the true mean value using a confidence level of 95%, if the true population variance is known to be 140,6252 The sample size must be at least (Round up to the nearest whole number)
In a sample of n= 11 lichen specimens, the researchers found the mean and standard deviation of the amount of the radioactive element, cesium- 137, that was present to be 0.009 and 0.003 microcurie per milliliter, respectively. Suppose the researchers want to increase the sample size in order to estimate the mean μ to within 0.002 microcurie per milliliter of its true value, using a 95% confidence interval. Complete parts a through c. a. What is the confidence level desired...
8. value: 10.00 points An experiment was conducted to determine the effectiveness of a method designed to remove oil wastes found in soil. Three contaminated soil samples were treated. After 95 days, the percentage of contamination removed from each soil sample was measured, with a mean of 49.3 percent and a standard deviation of 1.5 percent. If we wished to narrow the boundary around u for a 98 percent confidence interval to within 0.5 percent, how many soil samples should...
(3 points) The Highway Safety Department wants to study the
driving habits of individuals. A sample of 28 cars traveling on a
particular stretch of highway revealed an average speed of 69.9
miles per hour with a standard deviation of 4.2 miles per hour.
Round to 4 decimal places.
1.Calculate a 95% confidence interval for the true mean speed of
all cars on this particular stretch of highway.
( , )
2. What sample size is needed to estimate the...
a through d please
People were polled on how many books they read the previous year. Initial survey results indicate that s= 15.3 books. Complete parts (a) through (d) below. Click the icon to view a partial table of critical values. (a) How many subjects are needed to estimate the mean number of books read the previous year within four books with 95% confidence? This 95% confidence level requires subjects. (Round up to the nearest subject) (b) How many subjects...
A survey of 978 online shoppers was conducted In response to the question of what would influence the shopper to spend more money online for a certan year, 26% said tree ship , 19% said offering discounts while shopping, and 7% said product reviews Ca plete parts a through d below a. Construct a 95% confidence interval esin ate of the population propo tin « of online shoppers who would be infue ced to spend more money online with free...
7. in an area. A sample survey is to be conducted to determine the mean family income The question is, how many families should be sampled? In order to get more information about the area, a small pilot survey was conducted, and the standard deviation dollars. of the sample was conducted to be five hundred Ine spoOnsor of the survey wants you to use the ninety-nine percent confidence coefficient. Further, if you find the sample mean family income to be...
3. An IQ test is designed so that the mean is 100 and the standard deviation is 19 for the population of adults. Find the sample size necessary to estimate the mean IQ score of nurses such that it can be said with 99 % confidence that the sample mean is within 5 IQ points of the true mean. Assume that o = 19 and determine the required sample size using technology. The required sample size is _ (Round up...
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