The number of days (X) after mailout it takes a utility company to receive payment for a customer’s bill is a normal random variable with a mean of 31 days and a standard deviation of 6 days.About 16% of bills will be received earlier than days after mailout.

The number of days (X) after mailout it takes a utility company to receive payment for a customer’s bill is a normal random variable with a mean of 31 days and a standard deviation of 6 days.The probability is 0.997 that a bill will be received between which of the following number of days? (13, 49) (19, 43) (25, 37)

The number of days (X) after mailout it takes a utility company to receive payment for a customer’s bill is a normal random variable with a mean of 31 days and a standard deviation of 6 days.The latest 2.5% of bills will be received more than how many days after mailout? 13 19 25 31 37 43 49Question 7Type numbers in the boxes.10 pointsAccording to the Bureau of Labor Statistics, in May 2014 the mean hourly wage of a social worker was $28.08 with a standard deviation of $1.97. Jeronica is a social worker with an hourly wage of $31.60. What is Jeronica’s z-score? (Round your answer to 2 decimal places.)Question 8Select one answer.10 pointsThe time it takes a surgeon to complete a laproscopic surgery to remove the gall bladder is normally distributed with a mean of 132.4 minutes and a standard deviation of 15.7 minutes. A patient’s risk of complications is increased the longer he is in surgery. An unusually risky surgery is one that is in the top 4% of all surgery lengths.What is the minimum surgery length (in minutes) that would be considered unusually risky? Note: Answers are rounded to 1 decimal place. 159.9 minutes 147.5 minutes 104.9 minutes 247.4 minutes

The post office, which has separate lines at different windows, determines that the standard deviation for customer waiting times on Friday afternoons is 7.2 minutes. The post office decides to experiment with a single, main waiting line. For a random sample of 25 customers, it is found that the waiting times have a standard deviation of 3.5 minutes on a Friday afternoon. At a 5% significance level, the post office wants to test the assertion that a single line results in less variation in waiting times for customers. Give your conclusion.

The amount of time that customers wait in line during peak hours at one bank is normally distributed with a mean of 12 minutes and a standard deviation of 2 minutes. What is the probability that a customer will wait under 14 minutes?

A company audit showed that of 618 bills that were sent out, 380 were paid on time, 144 were paid up to 30 days late, 57 were paid between 31 and 90 days late, and 37 remained unpaid after 90 days. One bill is selected at random.Part: 0 / 20 of 2 Parts CompletePart 1 of 2(a) What is the probability that the bill was paid on time? Round your answer to four decimal places.The probability that the bill was paid on time is 1.6263