# Question: It has been reported that the average U S teenager sends

It has been reported that the average U.S. teenager sends 80 text messages per day. For purposes of this exercise, we will assume the daily number of text messages sent is normally distributed with a standard deviation of 15.0 messages. For a randomly selected group of 10 teenagers, and considering these persons to be a simple random sample of all U.S. teens, what is the probability that the group will send at least 900 text messages (i.e., a sample mean of at least 90 messages per teen) next Wednesday?

## Relevant Questions

The average length of a hospital stay in general or community hospitals in the United States is 5.5 days. Assuming a population standard deviation of 2.5 days and a simple random sample of 50 patients, what is the ...A simple random sample with n = 200 is drawn from a binomial process in which π = 0.6. Determine the following probabilities for p = the proportion of successes: a. P (0.50 ≤ p) b. P (0.65 ≤ p ≤ 0.70) c. P (p $ 0.70) What is meant by a finite population and how can this affect the sampling distribution of a mean or a proportion? Using the procedures in Computer Solutions 8.1 as a general guide, simulate 150 simple random samples of size n = 4 from a normal distribution with a mean of 80 and a standard deviation of 20. Determine the mean and the ...Given the following probability distribution for an infinite population with the discrete random variable, x: a. Determine the mean and the standard deviation of x. b. For the sample size n 5 2, determine the mean for each ...Post your question