# Question: A psychologist has devised a stress test for dental patients

A psychologist has devised a stress test for dental patients sitting in the waiting rooms. According to this test, the stress scores (on a scale of 1 to 10) for patients waiting for root canal treatments are found to be approximately normally distributed with a mean of 7.59 and a standard deviation of .73.

a. What percentage of such patients have a stress score lower than 6.0?

b. What is the probability that a randomly selected root canal patient sitting in the waiting room has a stress score between 7.0 and 8.0?

c. The psychologist suggests that any patient with a stress score of 9.0 or higher should be given a sedative prior to treatment. What percentage of patients waiting for root canal treatments would need a sedative if this suggestion is accepted?

a. What percentage of such patients have a stress score lower than 6.0?

b. What is the probability that a randomly selected root canal patient sitting in the waiting room has a stress score between 7.0 and 8.0?

c. The psychologist suggests that any patient with a stress score of 9.0 or higher should be given a sedative prior to treatment. What percentage of patients waiting for root canal treatments would need a sedative if this suggestion is accepted?

**View Solution:**## Answer to relevant Questions

According to the U.S. Department of Agriculture, the average American consumed 54.3 pounds (approximately seven gallons) of salad and cooking oils in 2008 (www.ers.usda.gov/data/foodconsumption). Suppose that the current ...Find the value of z so that the area under the standard normal curve a. From 0 to z is .4772 and z is positive b. Between 0 and z is (approximately) .4785 and z is negative c. In the left tail is (approximately) .3565 d. In ...The management of a supermarket wants to adopt a new promotional policy of giving a free gift to every customer who spends more than a certain amount per visit at this supermarket. The expectation of the management is that ...For a binomial probability distribution, n = 120 and p = .60. Let x be the number of successes in 120 trials. a. Find the mean and standard deviation of this binomial distribution. b. Find P(x < 69) using the normal ...Johnson Electronics makes calculators. Consumer satisfaction is one of the top priorities of the company’s management. The company guarantees the refund of money or a replacement for any calculator that malfunctions within ...Post your question