For a certain online store, the distribution of number of purchases per hour is approximately normal with mean 1,200 purchases and standard deviation 200 purchases. For what proportion of hours will the number of purchases at the online store exceed 1,400? 68% B 32% 16% 5% E 2.5%

The distribution of hourly sales for a local family owned store is normally distributed with a mean of $225 per hour and a standard deviation of $75 per hour. Which of the following intervals contains the middle 95% of hourly sales

The manager of a computer shop is recording the time taken for customers to decide of which computer and accessories they buy from the time they enter the store. From the previous data, it is known that the average ‘decision’ time was 45 minutes. The manager assumes a normally distributed population with a standard deviation of 10 minutesa)  What is the probability that a customer will take more than 60 minutes?b)  What proportion of customers will take between 35 and 60 minutes?

55. A small company records the number of online orders it receives each day for a week (Monday to Sunday). The numbers of orders are as ps: follows: 10, 12, 15, 8, 20, 15, and 18. What is the standard deviation of the number of orders? A. 5.87 B. 4.67 C. 4.28 D. 1.36

Dave drives to work each morning at about the same time. His commute time is normally distributed with a mean of 50 minutes and a standard deviation of 6 minutes.  What percentage of the time will his commute time be greater than 58 minutes?

A bookstore sells books for $2, $3, and $5. Let random variable X = "amount of money for one book."Look at the relative-frequency table below representing the amount of money spent on one item and the relative frequencies with which customers purchase them.x P(X = x)2 .723 .155 .13If the expected amount of money spent by a customer is $2.54, what is the standard deviation?