In a survey, 16 people were asked how much they spent on their child's last birthday gift. The results were roughly bell-shaped with a mean of $33 and standard deviation of $7. Find the margin of error at a 98% confidence level. Give your answer to two decimal places.

On a nationwide math test, the mean was 57 and the standard deviation was 4. If Roberto scored 90, what was his z-score?

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?

Find the length that separates premature babies from those who are not premature.

A survey was conducted that asked 972 people how many books they had read in the past year. Results indicated that x=14.1 books and s=16.6 books. Construct a 95​% confidence interval for the mean number of books people read. Interpret the interval. Construct a 95​% confidence interval for the mean number of books people read and interpret the result. Select the correct choice below and fill in the answer boxes to complete your choice. ​(Use ascending order. Round to two decimal places as​ needed.)     A. If repeated samples are​ taken, 95​%   {    } of them will have a sample mean between nothing and nothing.   B. There is a 95​% probability that the true mean number of books read is between {      }nothing and {      }nothing.   C. There is 95​% confidence that the population mean number of books read is between {      }nothing and {      }nothing.

The average person uses 130 gallons of water daily. If the standard deviation is 35 gallons , find the probability that the mean of a randomly selected sample of 25 people will be between 110 and 135 gallons.Assume the variable is normally distrubuted

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.

According to the U.S. Census, the average adult woman is the United States is 65 inches tall and the standard deviation is 3 inches.  If Zsike is 67 inches tall, what is her z-score?

You are told that a set of data includes one score which is 0.8.The standard deviation for the set is 0. Can you give the mean of the set and say anything else about the six other scores in the set?

We are interested in assessing the number of ropes a person can jump rope. We have a random sample of 31 people and find that the average person can jump rope 13.6 times with a standard deviation of 3.4. What is the 90% confidence interval for the actual average number of ropes a person can jump? Enter your answers accurate to one decimal place. Can we conclude that the actual average number of ropes a person can jump is at most 14.1? Yes O No Not enough information to determine this Beyond representative sampling, what assumptions are needed to satisfy the requirements for this confidence interval? OX binomial, np 25 and nq 25 OX normal or n ≥ 30 OX normal and n ≥ 30 OX~ binomial and at least 5 successes and failures N N N Submit Question