The results of a national survey showed that on average, adults sleep 6.7 hours per night. Suppose that the standard deviation is 1.4 hours 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 3.9 and 9.5 hours per day. Enter your answer as a percentage. % (b) What is the z-value for an adult who sleeps 8 hours per night? (c) What is the z-value for an adult who sleeps 6 hours per night?

Q: On a standard measure of hearing ability, the mean is 300 and the standard deviation is 20. Give the…

A: Given data ,Mean u=300S.D σ=20

Q: A large number of applicants for admission to graduate study in business are given an aptitude test.…

A:

Q: How high must a 2016 Vehicles gas mileage be to fall in the top 15% of all vehicles? normal mean is…

A: Given information: normal mean is 23.0mpg standard deviation is 4.9mpg

Q: The U.S. Census Bureau conducts a study to determine the time needed to complete the short form. The…

A: Given Data Population Mean,μ = 8.2 Population Standard Deviation,σ = 2.2 sample…

Q: standardized test has a pop. mean of 152 and a standard deviation of 16. Jenny has a score of 143.…

A: Given that Mean=M=152, Standard Deviation=Sd=16, Jenny score=X=143

Q: ez scores to compare the given values. The tallest living man at one time had a height of 228 cm.…

A: It is given that  Mean, μ = 174.11 Standard deviation, σ = 5.72 Z-Score, Z = ( X - μ )/σ