5. NetCast provides cable TV and internet services to its customers. Customer monthly bills have an average total cost of $212 and a standard deviation of $51. Roughly what percentage of customers have a monthly bill between $145.70 and $278.30

6. A car salesman randomly selected 15 days he has worked and recorded the number of cars he sold that day. The data are as follows: {0, 1, 1, 1, 1, 1, 1, 2, 2, 2, 3, 4, 5, 6, 9}. a) Compute the mean and standard deviation of this data set. (include units and use appropriate symbols) b) Does the data set contain any outliers? If so, what data point(s) is an outlier? Explain how you have reached your conclusion. No credit will be given is not explanation is present.

4.(5pts each) Coffeebucks is trying to estimate the percentage of people in Anytown that earn between $60,000 and $120,000. Local tax information shows the mean income is $90,000 with a standard deviation of $22,000 and that generally the income levels follow a normal distribution.

a) What percentage of customer bills exist between $24k and $156k?

b) Compute the z-score for a an income level of $100,000. Interpret the meaning of this value.

c) Suppose that we want to know at what percentile $100,000 lies. Would it be reasonable for someone to suggest that it is at the 45th percentile? Why or why not?