What is Your Sleep Position? ll UK adults who start sleep in this position. Use the...
The results of a national survey showed that on average, adults sleep 6.7 hours per night. Suppose that the standard deviation is 1.9 hours and that the number of hours of sleep follows a bell-shaped distribution. If needed, round your answers to two decimal digits. (a) Use the empirical rule to calculate the percentage of individuals who sleep between 2.9 and 10.5 hours per day. Enter your answer as a percentage. (b) What is the z-value for an adult who...
The results of a national survey showed that on average, adults sleep 6.6 hours per night. Suppose that the standard deviation is 1 hour and that the number of hours of sleep follows a bell-shaped distribution. If needed, round your answers to two decimal digits. If your answer is negative use "minus sign". (a) Use the empirical rule to calculate the percentage of individuals who sleep between 4.6 and 8.6 hours per day. Enter your answer as a percentage. (b)...
The results of a national survey showed that on average, adults sleep 6.3 hours per night. Suppose that the standard deviation is 1.4 hours. (a) Use Chebyshev's theorem to calculate the minimum percentage of individuals who sleep between 3.5 and 9.1 hours. (b) Use Chebyshev's theorem to calculate the minimum percentage of individuals who sleep between 2.8 and 9.8 hours. (c) Assume that the number of hours of sleep follows a bell-shaped distribution. Use the empirical rule to calculate the...
Students who get more sleep get better grades. You want to estimate the hours of sleep per night that a college student gets. You select 29 students; on average they slept 6.2 hours with a standard deviation of 1.8 hours. Should a z-distribution or t-distribution be used in the analysis?
Question 7 5 pts According to research, the amount of sleep per night for U.S adults follows a normal distribution with a mean p = 7.25 hours and standard deviation o - 1.25 hours. Determine the proportion of people who get between 5.0 and 9.0 hours of sleep per night. Use the provided Standard Normal Table (Z table), and provide the proportion as a decimal rounded to four decimal places.
Students who get more sleep get better grades. You want to estimate the hours of sleep per night that a college student gets. You select 29 students; on average they slept 6.2 hours with a standard deviation of 1.8 hours. The standard error is 0.334. In order to be 90% confident of an estimate of the population mean, what is the critical value? A- 1.640 B- 1.960 C- 1.699 D- 1.701 E- 2.064
Find the sample size, n, needed to estimate the percentage of adults who have consulted fortune tollers. Use a 0.02 margin of error, use a confidence level of 90%, and use results from a prior poll suggesting that 16% of adults have consulted fortune tellers. n= (Round up to the nearest integer.)
A researcher wishes to estimate the percentage of adults who support abolishing the penny. What size sample should be obtained if he wishes the estimate to be within 4 percentage points with 90% confidence if (a) he uses a previous estimate of 38%? (b) he does not use any prior estimates? Click here to view the standard normal distribution table (page 1). Click here to view the standard normal distribution table (page 2). (a) na (Round up to the nearest...
In a survey1 of 1000 American adults conducted in April 2012, 43% reported having gone through an entire week without paying for anything in cash. Test to see if this sample provides evidence that the proportion of all American adults going a week without paying cash is greater than 40%. Use the fact that a randomization distribution is approximately normally distributed with a standard error of SE=0.016. Show all details of the test and use a 5% significance level. 1‘‘43%...
Find the sample size, n, needed to estimate the percentage of adults who have consulted fortune tellers. Use a 0.07 margin of error, use a confidence level of 90%, and use results from a prior poll suggesting that 17% of adults have consulted fortune tellers. n =