Customers arrive at a one-person barber shop with an average interarrival time of 20 minutes. The average time for a haircut is 12 minutes, exponentially distributed. a. The owner wishes to have enough seats in the waiting area so that on the average no more than 5% of the arriving customers will have to stand. How many seats should be provided? b. Suppose that there is only sufficient space in the waiting area for five seats. What is the probability that an arriving customer will not find a seat?

Data on the gasoline tax per gallon (in cents) as of a certain date for the 50 U.S. states and the District of Columbia are shown below. State Gasoline Taxper Gallon State Gasoline Taxper Gallon Alabama 19.1 Missouri 17.2 Alaska 9.1 Montana 27.7 Arizona 19.1 Nebraska 27.8 Arkansas 21.7 Nevada 23.7 California 37.1 New Hampshire 23.9 Colorado 23.4 New Jersey 14.5 Connecticut 25.1 New Mexico 19.0 Delaware 22.9 New York 33.9 District of   Columbia 23.4 North Carolina 35.4 North Dakota 23.1 Florida 30.7 Ohio 28.1 Georgia 26.6 Oklahoma 17.1 Hawaii 18.4 Oregon 30.1 Idaho 33.1 Pennsylvania 51.3 Illinois 33.0 Rhode Island 34.0 Indiana 28.9 South Carolina 16.9 Iowa 31.9 South Dakota 30.1 Kansas 24.9 Tennessee 21.3 Kentucky 25.9 Texas 20.1 Louisiana 21.0 Utah 30.0 Maine 31.5 Vermont 30.6 Maryland 32.7 Virginia 16.9 Massachusetts 26.6 Washington 44.5 Michigan 31.0 West Virginia 33.3 Minnesota 30.5 Wisconsin 33.0 Mississippi 18.3 Wyoming 24.1…

Mariah Jacobsen is the marketing manager at ABC Electronics, a major consumer electronics supplier in the northwest. Over the last five years, sales of the company's flagship product - the Wizer Anonymizer (the WA) - have been 45000, 45500, 44500, 46000 and 44000 units. This rate of sales is considered average for the product over the last twenty years or so. Ms. Jacobsen believes that the distribution of the WA's sales is normal with a standard deviation of 1500 units. If she were asked to make a forecast of next year's sales to upper management, what is the likelihood that she would be correct if she predicts sales between 43000 and 46000?

The brand manager for a brand of toothpaste must plan a campaign designed to increase brand recognition. He wants to first determine the percentage of adults who have heard of the brand. How many adults must he survey in order to be 90% confident that his estimate is within eight percentage points of the true population percentage? Complete parts (a) through (c) below. ... a) Assume that nothing is known about the percentage of adults who have heard of the brand. n= (Round up to the nearest integer.)