You wish to estimate the mean number of travel days per year for salespeople. The mean of a small pilot study was 150 days, with a standard deviation of 40 days. If you want to estimate the population mean with 98% confidence and a margin of error of 4 days, how many salespeople should you sample? (Use z Distribution Table.) (Round "Z value to 3 decimal places and round your answer to the next whole number.) Number of outside salespeople

Think of your own example of a data set that would follow a normal distribution and explain why.

You want to know the percentage of utility companies that earned revenue greater than 94 million dollars. If the mean revenue was 60 million dollars and the data has a standard deviation of 15 million, find the percentage. Assume that the distribution is normal. Round your answer to the nearest hundredth.

In the Social Psychology course, you receive a score of 77 on the second exam. You are told that the standard deviation of the second exam is 8 and that your score is .75 standard deviations below the mean. a. What is the class mean of the second exam? b. Your friend scored a 70 on the second exam. How many standard deviations below the mean is your friend’s score?

This is math economics

It is often quoted that in a normal distribution, 95% of the data lies 1.96 deviations either side of the mean. How many deviations from the mean would 88 percent lie?

Mario's weekly poker winnings have a mean of $353 and a standard deviation of $67. Last week he won $185. How many standard deviations from the mean is that?

What does the standard deviation tell you about a set of data?

This looks like another problem. Read carefully. Sergio is doing a long hike and is carefully calculating his pack weight. An energy bar has mean weight 1.71 ounces and standard deviation 0.037. The weights of the bars are independent. A juice box has mean weight 7.1 ounces and standard deviation 0.25. The weights of the juice boxes are independent.  If he takes 3 energy bars and 5 juice boxes, what will be the MEAN of the total weight in pounds from these items? Hint: If W is the weight in ounces, then W/16 is the weight in pounds.

Find the proportion of Normally distributed observations with a z-score above -1.93. Give your answer to four decimal places.