
as 2009 Mansour conducted a survey to estimate the average number of the hours studied weekly...
4. A survey asked a random sample of 363 first-year students how many hours they studied during a particular week. The mean was 15.3 hours. Suppose we know that the population standard deviation is 8.5 hours. Construct a 90%, 95% and 99% confidence interval for the mean study time of all first year students at this university. Interpret the 90% confidence interval.
1. To determine the average number of hours spent studying by college students per week, a sample of 39 students was randomly selected, and found to spend an average of 17.1 hours per week, with a standard deviation of 4.3 hours. Find the 90% confidence interval for the mean number of hours spent studying per week by all college students. What is the upper and lower bound? 2. If I asked a random student how many hours they study per...
ame: A survey conducted by Sallie Mae and Gallup of 1404 respondents found that 323 students paid for their education by student loans. Find the 90% confidence of the true proportion of students who paid for their education by student loans. A survey of 1898 people found that 45% of the adults said that dandelions were the toughest weeds to control in their yards. Find the 95% confidence interval of the true proportion who said that dandelions were the toughest...
A scientific study was conducted to determine the hours of sleep that college students get per night. The college students surveyed slept an average of 7.8 hours per night. The margin of error of the survey was 0.5 hours. Construct a confidence interval for the average hours of sleep per night that college students get.
A survey of 225 Statistics students showed that they spend an average of 5.2 hours studying for the class. Assume σ=.4. a) Construct a 99% confidence interval to estimate the mean amount of time spent studying. b) Interpret the confidence interval in the context of the problem.
A random sample of community college students was asked the number of hours they sleep on a typical week-night during a given academic term. The sample data are as follows: 8 6 4 5 3 7 S 4 3 4 4 5 6 8 7 7 7 3 3 4 What is the 90% confidence interval estimate for the true mean amount of sleep time per night spent by community college students during a academic term? a) The data give...
We want to know the average number of hours financial advisors in your area work a month. You survey 76 random advisors and find the average hours they work per month is 189. You also believe that the population standard deviation is 20 hours a month. Give a 99% confidence interval for the estimated average number of hours financial advisors work per month. Confidence Interval Estimate for the Mean Data Population Standard Deviation 20 Sample Mean 189 Sample Size 76...
24. Find the minimum sample size required to estimate a population proportion with a margin of error = 0.05 a confidence level of 90%, and from a prior study, p is estimated to be .25 (a) 203 (b) 329 (c) 247 (d) 396 (e) 289 25. In a survey of 385 students at Broward College, North Campus, results revealed that 154 students were born outside of the USA. Construct a 96% confidence interval estimate for the proportion of students who...
In a study done by the Scottish government, the average weekly earnings for men were found to be substantially higher than for women. Specifically, the average gross individual weekly income for a random sample of men was £317; for a random sample of women, it was £172 (source: Social Focus on Men and Women, scotland.gov.uk). If the samples included 1500 men and 1200 women, and the sam- ple standard deviations were £89 for the men and £67 for the women,...
You would like to conduct a survey to estimate the average number of hours of sleep UWEC students get per night. You would like a 95% confidence interval whose width is no more than 0.5 hours. a. What is the margin of error, ?? b. What is ?, the level of significance that corresponds to the confidence level? c. What is the multiplier (??/2)? e. Find the smallest sample size that would be reasonable to achieve your goal of a...