Instructions: Using the information given, determine whether a normal approximation is appropriate, and then answer the questions. According to recent research, internet users spend an average of 2.3 hours per day on social media, with a standard deviation of .3. It is thought that internet usage follows a normal distribution. A random sample of 5 internet users is selected. Is a normal approximation appropriate? Why or Why not? What is the mean of the sampling mean? What is the standard deviation of the sampling proportion? (round to thousandths) Find the probability that the average time spent on social media of the sample is less than 2 hours. P(x < 2) =

Use the Empirical Rule. The mean speed of a sample of vehicles along a stretch of highway is 68 miles per​ hour, with a standard deviation of 3 miles per hour. Estimate the percent of vehicles whose speeds are between 65 miles per hour and 71 miles per hour.​ (Assume the data set has a​ bell-shaped distribution.) Approximately nothing​% of vehicles travel between 65 miles per hour and 71 miles per hour.

A standardized test has a mean of 88 and a standard deviation of 12. What is the score at the 90th percentile? a. 103.36 O b. 112.00 O c. 91.00 O d. 90.00

The average driver spends $39 at the gas station each week with a standard deviation of $11. Assuming that the amount a driver spends on gas follows a normal distribution; find the percentage of drivers who spend: 1. More than $67? 2. Less than $25? 3. Between $25 and $67