a survey will be conducted to gather salary information for an urban area. It is planned to block the factor of gender in the sampling. The tolerance of error is ± $5,000, salary distribution standard deviation is $20,000, how many employees need to be surveyed with 90% and 99% confidence respectively?
a survey will be conducted to gather salary information for an urban area. It is planned...
4. A health behaviors survey conducted in a large urban area includes a question about whether a person is a smoker. The company conducting the survey decides to increase the size of its random sample of survey participants from 1,500 people to approximately 20,000 people. This change will most likely have which of the following effects? a. increasing the standard error of the estimate b. decreasing the variability of the estimate c. no effect on survey statistics because the population...
A survey is being planned to determine the mean amount of time corporation executives watch television. A pilot survey indicated that the mean time per week is 12 hours, with a standard deviation of 3.5 hours. It is desired to estimate the mean viewing time within one-quarter hour. The 90% level of confidence is to be used. How many executives should be surveyed? (Round your z-score to 2 decimal places and round your final answer to the next whole number.)
A survey is being planned to determine the mean amount of time corporation executives watch television. A pilot survey indicated that the mean time per week is 13 hours, with a standard deviation of 2.0 hours. It is desired to estimate the mean viewing time within one-quarter hour. The 95% level of confidence is to be used. (Use z Distribution Table.) How many executives should be surveyed? (Round your z-score to 2 decimal places and round up your final answer...
9. A group of statistics students decided to conduct a survey at their university to find the average (mean) amount of time students spent studying per week. Assuming a population standard deviation of three hours, what is the required sample size if the error should be less than a half hour with a 99% level of confidence? 10.University officials say that at least 70% of the voting student population supports a fee increase. If the 95% confidence interval estimating the...
A survey has been conducted to estimate the usage of high-speed internet in the local area. 154 households were surveyed and asked whether they used high-speed internet at their home. 84 households surveyed responded that they do have a high-speed internet connection at home. a)Calculate the margin of error for the 95% confidence interval for the proportion of households that have a high-speed internet connection. Give your answer as a decimal to 3 decimal places. margin of error = b)Calculate...
Wisconsin Public Radio wants to duplicate a survey conducted in 2011 that found that 68% of adults living in Wisconsin felt that the country was going in the wrong direction. How many people would need to be surveyed for a 90% confidence interval to ensure the margin of error would be less than 3%. Be sure to show all your work and round appropriately. (4 points)
A survey is being planned to determine the average amount of time preschool children watch television. A pilot survey indicated that the mean time per week is 12 hours, with a standard deviation of 3 hours. It is desired to estimate the mean viewing time within one-quarter hour. The 0.95 degree of confidence is to be used. How do you calculate how many preschool children should be surveyed? Why is it important to make sure your sample size is sufficient?
The following data were obtained from a salary survey of
Canadian laboratory employees in 2006. The salaries were rounded to
the nearest $10,000 and there were 333 respondents.
See picture.
(a) Determine the mean, median, and mode salaries of these lab
employees.
(b) Determine the standard deviation of the average
salaries.
(c) Calculate the skew and kurtosis of this distribution (you
can assume that the population mean and
standard deviation are the same as the sample values).
3. The folowing...
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...
32. An independent group of food service personnel conducted a survey on tipping practices in a large metropolitan area. They collected information on the percentage of the bill left as a tip for 25 randomly selected bills. The average tip was 18.3% of the bill with a standard deviation of 2.7%. a. Construct an interval to estimate the true average tip (as a percent of the bill) with 99% confidence. b. Interpret the interval, and state any assumptions that were...