# A banker finds that the number of times people use automated-teller machines in a year are normally distributed with a mean of 40.0 and a standard deviation of 11.4. What is the percentage of customers who use them less than 25 times?

9.34%.

Given that the distribution is said to be normal, we can use a z-score table to obtain the desired percentage after standardizing the values we gave to a z-score value.

We simply use a z-score table to find the z-score we just determined (-1.32) and use the table to find the left-tail area under the normal curve in order to determine the percentage of customers who use the ATMs fewer than 25 times.

This translates to an area of 0.0934, or approximately 9.34% of all customers, according to a single table.

By signing up, you agree to our Terms of Service and Privacy Policy

- What is the difference between a normal distribution, binomial distribution, and a Poisson distribution?
- A banker finds that the number of times people use automated-teller machines in a year are normally distributed with a mean of 40.0 and a standard deviation of 11.4. What is the percentage of customers who use them less than 25 times?
- Let z be a random variable with a standard normal distribution. Find the indicated probability. What is the probability that P(z ≤ 1.18)?
- How do you find the area under the standard normal curve for the z-score interval z < -1.6?
- In a standard normal distribution, what is the probability that #P(-.89<z<0)#?

- 98% accuracy study help
- Covers math, physics, chemistry, biology, and more
- Step-by-step, in-depth guides
- Readily available 24/7