A random sample of 47 cars in the drive-thru of a popular fast food restaurant revealed an average bill of $16.60 per car. The population standard deviation is $4.86. Estimate the mean bill for all cars from the drive-thru with 91% confidence. Round intermediate and final answers to two decimal places.

The average chef at a restaurant earns $17 an hour with a deviation of $1.75. What are the chances that someone is earning more than $20 an hour?

The distances golf balls travel under laboratory testing conditions are normally distributed. The mean is 313 yards. The probability the golf ball travels further than 322 yards is 0.13. Find the probability a randomly selected golf ball travels between 304 yards and 322 yards. Express the answer as a decimal value rounded to the nearest hundredth.

A line for tickets to a broadway show had a mean waiting time of 20 minutes with a statistic deviation of 5 minutes. What Percentage of People in line waited for more than 28 minutes?

A population has a Mean of 100 and a standard deviation of 15.  A sample of 20 college students is measured and the Sample mean is 125.  What is the standard error?  Show the math.

The prices of all college textbooks follow a bell-shaped distribution with a mean of $108 and a standard deviation of $21. What percentage of the price that is more than 140? Show your works and read the table.

A class has an equal number of boys and girls. The boys all got78% on a test and the girls all got 84%.. What are the mean and standard deviation of thetest scores for the entire class?

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?

A psychologist created a questionnaire to assess people's aggression. Assume that the questionnaire responses are regularly distributed with a standard deviation of 100. Assume that 15% of the scores are higher than 700. Determine the mean of the score distribution. Calculate your intermediate results to at least four decimal places. Round your answer to the nearest decimal point.