NJ residents’ water consumption per day follows approximately a normal distribution with a mean of 20 gallons per day, and a standard deviation of 8 gallons per day.

a. Find the probability that a randomly selected resident consumes at least 11 gallons of water per day.

b. Find the probability that a randomly selected resident consumes at least 30 gallons of water per day.

c. A sample of n=36 residents is taken in NJ. What is the probability that the sample mean water consumption is at least 11 gallons per day?

d. For the same sample, what is the probability that the sample mean water consumption is at least 30 gallons per day? At least 22 gallons a day?

e. 95% of NJ residents consume at most ____________ gallons per day.

f. 95% of all samples of 36 NJ residents have a mean of at most ___________ gallons a day.

g. 90% of NJ residents consume between ____________ and _______________ gallons per day.

h. 90% of sample averages of samples of size 36 of NJ residents are between ______ and _____ gallons a day.

Answer rating: 100% (QA)

let X is a vv representing NJ residents water consumption per da... View the full answer