1. According to the data released by the Chamber of Commerce of a certain city, the weekly wages of factory workers are normally distributed with a mean of $760 and standard deviation of $70. Find the probability that a worker selected at random from the city makes the following weekly wage. (Round your answers to four decimal places.)

(a) less than $760

(b) more than $949

(c) between $690 and $830

1. On average, a student takes 90 words/minute midway through an advanced court reporting course at the American Institute of Court Reporting. Assuming that the dictation speeds of the students are normally distributed and that the standard deviation is 10 words/minute, find the probability that a student randomly selected from the course can take dictation at the following speeds. (Round your answers to four decimal places.)

(a) more than 120 words/minute

(b) between 80 and 120 words/minute

(c) less than 80 words/minute

1. The tread lives of the Super Titan radial tires under normal driving conditions are normally distributed with a mean of 60,000 mi and a standard deviation of 5000 mi. (Round your answers to four decimal places.)

What is the probability that a tire selected at random will have a tread life of more than 55,250 mi?

Determine the probability that four tires selected at random still have useful tread lives after 55,250 mi of driving. (Assume that the tread lives of the tires are independent of each other.)

1. To be eligible for further consideration, applicants for certain civil service positions must first pass a written qualifying examination on which a score of 85 or more must be obtained. In a recent examination, it was found that the scores were normally distributed with a mean of 75 points and a standard deviation of 10 points. Determine the percentage of applicants who passed the written qualifying examination. (Round your answer to two decimal places.)

2. The scores on an economics examination are normally distributed with a mean of 71 and a standard deviation of 16. If the instructor assigns a grade of A to 14% of the class, what is the lowest score a student may have and still obtain an A? (Round your answer to two decimal places.)

3. The speeds (in miles per hour) of motor vehicles on a certain stretch of Route 3A as clocked at a certain place along the highway are normally distributed with a mean of 61.6 mph and a standard deviation of 5.95 mph. What is the probability that a motor vehicle selected at random is traveling at the following speeds? (Round your answers to four decimal places.)

(a) more than 64 mph

(b) less than 60 mph

(c) between 64 and 68 mph

1. Use the appropriate normal distribution to approximate the resulting binomial distribution.

A basketball player has a 80% chance of making a free throw. (Assume that the throws are independent of each other.) What is the probability of her making 100 or more free throws in 110 trials? (Round your answer to four decimal places.)

1. Use the appropriate normal distribution to approximate the resulting binomial distribution.

Jorge sells magazine subscriptions over the phone. He estimates that the probability of his making a sale with each attempt is 0.09. What is the probability of Jorge making more than 15 sales if he makes 80 calls? (Round your answer to four decimal places.)

1. Use the appropriate normal distribution to approximate the resulting binomial distribution.

The manager of Madison Finance Company has estimated that, because of a recession year, 3% of its 500 loan accounts will be delinquent. If the manager's estimate is correct, what is the probability that 24 or more of the accounts will be delinquent? (Round your answer to four decimal places.)