# statistics

posted by .

mean = 60 wpm
standard deviation= 15 wpm

a.What is the probability that a randomly selected typist's net rate is at most 60 wpm? less than 60 wpm?

b. What is the probability that a randomly selected is between 45 and 90 wpm?

• statistics -

Z = (score-mean)/SD

Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportions/probabilities related to the Z scores.

## Similar Questions

1. ### Statistics

9. Assume the weight, W, of a randomly selected adult has a normal distribution with a mean of 175 pounds and a standard deviation of 10 pounds.. Find the probability, P(W < 190), that a randomly selected adult weighs less than …
2. ### Statistics

Suppose that the birth weight of newborn babies in the U.S is normally distributed with a mean of 7 pounds and a standard deviation of 1.6 pounds. Let the random variable X be the birth weight of a randomly selected record of live …
3. ### Statistics

Scores on a visual perception test are normally distributed with a mean of 2020 and a standard deviation of 250. a)If one subject is randomly selected and tested, find the probability of a score greater than 1800 b)if 50 subjects are …
4. ### statistics

Scores on a visual perception test are normally distributed with a mean of 2020 and a standard deviation of 250. a)If one subject is randomly selected and tested, find the probability of a score greater than 1800 b)if 50 subjects are …
5. ### statistics

Assume that women's heights are normally distributed with a mean given by u=64.6 in and a standard deviation given by 0=2.8in. a) If 1 woman is randomly selected, find the probability that her height is less than 65in. b) If 49 women …
6. ### Statistics (36)

For borrowers with good credit scores, the mean debt for revolving and installment accounts is \$15,015 (BusinessWeek, March 20, 2006). Assume the standard deviation is \$3,730 and that debt amounts are normally distributed. a. What …
7. ### Statistics/Probability

Assume that womenâ€™s heights are normally distributed with a mean given by μ = 63.4 in, and a standard deviation given by σ = 2.3 in. (a) If 1 woman is randomly selected, find the probability that her height is less than …
8. ### math

Test scores on a university admissions test are normally distributed, with a mean of 500 and a standard deviation of 100. a. What is the probability that a randomly selected applicant scores between 425 and 575?
9. ### Statistics

An automatic machine in a manufacturing process is operating properly if the length of an important subcomponent is normally distributed with a mean μ = 80 cm and a standard deviation σ = 2 cm. a) Find the probability that …
10. ### math

Justine's typing speed is 36 wpm (words per minute). She finished a job in 5 hours. How long would the same job have taken her if she typed 48 wpm?

More Similar Questions