1.Assume thatxhas a normal distribution with the specified mean and standard deviation. Find the indicated probability. (Round your answer to four decimal places.)=5.0;=1.1P(7x9) =

2.Assume thatxhas a normal distribution with the specified mean and standard deviation. Find the indicated probability. (Round your answer to four decimal places.)=102;=17P(x120) =

3.Assume thatxhas a normal distribution with the specified mean and standard deviation. Find the indicated probability. (Round your answer to four decimal places.)=2.8;=0.40P(x2)

4.Findzsuch that4.3%of the standard normal curve lies to the left ofz. (Round your answer to two decimal places.) z=

5.Findzsuch that6%of the standard normal curve lies to the right ofz. (Round your answer to two decimal places.)z=

6.Findzsuch that4.8% of the standard normal curve lies to the right ofz. (Round your answer to three decimal places.)z=

7.Find thezvalue such that39%of the standard normal curve lies betweenzandz. (Round your answer to two decimal places.)z=

8.A person's blood glucose level and diabetes are closely related. Letxbe a random variable measured in milligrams of glucose per deciliter(1/10 of a liter)of blood. Suppose that after a12-hourfast, the random variablexwill have a distribution that is approximately normal with mean=83and standard deviation=26.Note:After 50 years of age, both the mean and standard deviation tend to increase. For an adult(under 50)after a12-hourfast, find the following probabilities. (Round your answers to four decimal places.)

(a)xis more than 60 (b)xis less than 110 (c)xis between 60 and 110 (d)xis greater than 125 (borderline diabetes starts at 125) 9.Porphyrin is a pigment in blood protoplasm and other body fluids that is significant in body energy and storage. Letxbe a random variable that represents the number of milligrams of porphyrin per deciliter of blood. In healthy circles,xis approximately normally distributed with mean=35and standard deviation=14.Find the following probabilities. (Round your answers to four decimal places.)

(a)xis less than 60 (b)xis greater than 16 (c)xis between 16 and 60 (d)xis more than 60 (This may indicate an infection, anemia, or another type of illness.) 10.Quick Start Company makes 12-volt car batteries. After many years of product testing, the company knows that the average life of a Quick Start battery is normally distributed, with a mean of45.4months and a standard deviation of7.7months.

(a) If Quick Start guarantees a full refund on any battery that fails within the 36-month period after purchase, what percentage of its batteries will the company expect to replace? (Round your answer to two decimal places.) % (b) If Quick Start does not want to make refunds for more than11%of its batteries under the full-refund guarantee policy, for how long should the company guarantee the batteries (to the nearest month)? months

11.The amount of money spent weekly on cleaning, maintenance, and repairs at a large restaurant was observed over a long period of time to be approximately normally distributed, with mean=$609and standard deviation=$38.

(a) If $646 is budgeted for next week, what is the probability that the actual costs will exceed the budgeted amount? (Round your answer to four decimal places.) (b) How much should be budgeted for weekly repairs, cleaning, and maintenance so that the probability that the budgeted amount will be exceeded in a given week is only0.08? (Round your answer to the nearest dollar.) $