Questions from Business Statistics

Q: A random sample of size 81 is drawn from a population with

A random sample of size 81 is drawn from a population with a standard deviation of 12. If only 18% of the time a sample mean greater than 300 is obtained, what is the mean of the population?

Q: Find the probability in each case. a) N =

Find the probability in each case. a) N = 1000, n = 60, μ = 60, and σ = 6; P(x̅< 76.5) =? b) N = 90, n = 36, μ = 108, and σ = 3.46; P(107 < x̅ < 107.7) =? c) N = 250, n = 100, μ = 35.6, and σ = 4.89;...

Q: The Statistical Abstract of the United States published by the U.

The Statistical Abstract of the United States published by the U.S. Census Bureau reports that the average annual consumption of fresh fruit per person is 99.9 pounds. The standard deviation of fresh...

Q: Suppose the average checkout tab at a large supermarket is $65

Suppose the average checkout tab at a large supermarket is $65.12, with a standard deviation of $21.45. Twenty-three percent of the time when a random sample of 45 customer tabs is examined, the sampl...

Q: Suppose a subdivision on the southwest side of Denver, Colorado,

Suppose a subdivision on the southwest side of Denver, Colorado, contains 1500 houses. The subdivision was built in 1983. A sample of 100 houses is selected randomly and evaluated by an appraiser. If...

Q: Studies have shown that about half of all workers who change jobs

Studies have shown that about half of all workers who change jobs cash out their 401(k) plans rather than leaving the money in the account to grow. The percentage is much higher for workers with small...

Q: According to Nielsen Media Research, the average number of hours of

According to Nielsen Media Research, the average number of hours of TV viewing by adults (18 and over) per week in the United States is 33 hours. Suppose the standard deviation is 7.9 hours and a rand...

Q: A given population proportion is .25. For the given value

A given population proportion is .25. For the given value of n, what is the probability of getting each of the following sample proportions? a) n = 110 and ˆp ≤ .21 b) n = 33 and ˆp > .24 c) n = 59 an...

Q: A population proportion is .58. Suppose a random sample of

A population proportion is .58. Suppose a random sample of 660 items is sampled randomly from this population. a) What is the probability that the sample proportion is greater than .60? b) What is the...

Q: Suppose a population proportion is .40, and 80% of

Suppose a population proportion is .40, and 80% of the time when you draw a random sample from this population you get a sample proportion of .35 or more. How large a sample were you taking?