A philosophy professor assigns letter grades on a test according to the following scheme. A: Top 13% of scores B: Scores below the top 13% and above the bottom 62% C: Scores below the top 38% and above the bottom 15% D: Scores below the top 85% and above the bottom 8% F: Bottom 8% of scores Scores on the test are normally distributed with a mean of 69.5 and a standard deviation of 9.5. Find the minimum score required for an A grade. Round your answer to the nearest whole number, if necessary.

Electricity bills: According to a government energy agenCy 2011 was $110. 10. Assume the amounts are normally distributed with standard deviation $21.00. Use the TI-84 Plus calculator to answer the following. electricity bil in the United States in (a) Find the 7th percentile of the bill amounts. (b) Find the 58th percentile of the bill amounts. (c) Find the median of the bill amounts. Round the answers to at least two decimal places.

Given the data, calculate the standard deviation for each: 1) 0.85, 0. 82, 0.83 2)0.10, 0.07, 0.05 3) 1.48, 1.43, 1.49 4) 0.58, 0.51, 0.58 5) 0.37, 0.28, 0.35

In each part, give the value of the standardized statistic (z-score) for the sample mean. 100, σ = 8, n = 4 (a) x = 88, μ = Z = (b) x = 88, μ = 100, σ = 8, n = 64 Z = (c) x = 10.63, μ = 10.0, σ = 7, n = 10,000 z =

In the 1992 presidential election, Alaska's 40 election districts averaged 1989 votes per district for President Clinton. The standard deviation was 568. (There are only 40 election districts in Alaska.) The distribution of the votes per district for President Clinton was bell-shaped. Let X = number of votes for President Clinton for an election district. (Source: The World Almanac and Book of Facts) Round all answers except part e. to 4 decimal places. a. What is the distribution of X? X ~ N( __ , __ ) b. Is 1989 a population mean or a sample mean? Select an answer _______. c. Find the probability that a randomly selected district had fewer than 2087 votes for President Clinton. _____ d. Find the probability that a randomly selected district had between 1905 and 2194 votes for President Clinton.______ e. Find the first quartile for votes for President Clinton. Round your answer to the nearest whole number. ______

Find the population variance and standard deviation as indicated: Population: 4,10,12,12,13,21

Find the sample mean x̄, median, variance s2,  and standard deviation s of the following data:     15  10  25  12  40