1) According to a Wall Street Journal article, 90% of all U.S. households have a cellular phone. (Tip: Binomial Distribution) a) If you call 8 households at random, what is the probability that more than six households have a cellular phone? b) For a sample of 25 households, find the expected value and the standard deviation of the number of households with cellular phones.

Have you ever tried to get out of jury duty? About 25% of those called will have an excuse to avoid jury duty.  If 12 people are called for jury duty: What is the probability that all 12 will be available to serve on the jury? What is the probability that 6 or more will not be available to serve on the jury? Find the expected number (average number) of those available to serve on the jury? What is the standard deviation?

A) The distribution of the number of gallons of water used for taking a shower in the UnitedStates are skewed right. Some people take long showers using as much as 63 gallons compared to the average of 17.2 gallons. A conservationist is interested in the mean number of gallons of water used in college apartments housing 4 students. Assuming a standard deviation of 4.2 gallons for all US showers, what is the probability that a random sample of 30 college student showers will have a mean water usage of more than 19 gallons of water? This question is for AP statistics about sampling distribution and normal model. Can you help me with this?

The result of a nationwide aptitude test in mathematics are normally distributed sith mean=63 and standard deviation =5 a. What is the probability of scores greater than 65? b. What is the probability of scores less than 65?