# Comparing z-scores and probability

Please see the attached file.

1. An article in USA Today stated that "Internal surveys paid for by directory assistance providers show that even the most accurate companies give out wrong numbers 15% of the time." Assume that you are testing such a provider by making 10 requests and also assume that the provider gives the wrong telephone number 15% of the time. Find the probability of getting at most, one wrong number. (Assume the Binomial distribution applies.)

0.347

0.544

0.653

0.456

2. Comparing Scores. Three students take equivalent tests of a sense of humor and, after the laughter dies down, their scores are calculated. Which is the lowest relative score?

1. A score of 144 on a test with a mean of 128 and a standard deviation of 34?

2. A score of 90 on a test with a mean of 86 and a standard deviation of 18?

3. A score of 18 on a test with a mean of 15 and a standard deviation of 5?

Answer 1.

Answer 2.

Answer 3.

Cannot determine from the information provided.

3. Comparing a z Score. Heights of women have a mean of 63.6 inches and a standard deviation of 2.5 inches. Julia Roberts, who is one of the most successful actresses in recent years, has a height that converts to a z score of 2.16. How tall (in inches) is Julie Roberts?

69 inches.

59 inches.

Can not convert z scores to inches, impossible to answer the question.

A sample size is not given; accordingly the standard error of the mean can not be calculated; impossible to answer the question.

https://brainmass.com/statistics/probability/195292

#### Solution Summary

The solution compares z-scores and probably for internal surveys from USA today.