In a study of long distance telephone calls, it was found that the lengths of the calls are normally distributed with a mean of 120.5 seconds and a standard deviation of 20.0 seconds. i. What is the probability that a particular call lasted less than 90.0 seconds or more than 130.0 seconds? ii. What is the probability that a particular call lasted more than 80.5 seconds? iii. What percentage of these calls lasted between 60 and 90 seconds? iv. What must be the length of a particular call be if only 10% of all calls are shorter?

Glencoe Algebra 1, Student Edition, 9780079039897, 0079039898, 2018
18th Edition
ISBN:9780079039897
Author:Carter
Publisher:Carter
Chapter10: Statistics
Section10.4: Distributions Of Data
Problem 19PFA
icon
Related questions
Question

In a study of long distance telephone calls, it was found that the lengths of the calls are
normally distributed with a mean of 120.5 seconds and a standard deviation of 20.0
seconds.

i. What is the probability that a particular call lasted less than 90.0
seconds or more than 130.0 seconds?
ii. What is the probability that a particular call lasted more than
80.5 seconds?
iii. What percentage of these calls lasted between 60 and 90
seconds?
iv. What must be the length of a particular call be if only 10% of all
calls are shorter?

Expert Solution
trending now

Trending now

This is a popular solution!

steps

Step by step

Solved in 4 steps with 4 images

Blurred answer
Knowledge Booster
Point Estimation, Limit Theorems, Approximations, and Bounds
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, statistics and related others by exploring similar questions and additional content below.
Recommended textbooks for you
Glencoe Algebra 1, Student Edition, 9780079039897…
Glencoe Algebra 1, Student Edition, 9780079039897…
Algebra
ISBN:
9780079039897
Author:
Carter
Publisher:
McGraw Hill