Azman uses his mobile phone for X minutes each day. X is a random variable which may be modelled by a normal distribution with mean 28 minutes and standard deviation 8 minutes. (a) Find the probability that on a particular day Azman uses his mobile phone for: less than 30 minutes (i) (ii) between 10 and 20 minutes (b) Calculate an interval, symmetrical about 28 minutes, within which X will lie on 80% of days.

Azman uses his mobile phone for X minutes each day. X is a random variable which may be modelled by a normal distribution with mean 28 minutes and standard deviation 8 minutes. (a) Find the probability that on a particular day Azman uses his mobile phone for: less than 30 minutes (i) (ii) between 10 and 20 minutes (b) Calculate an interval, symmetrical about 28 minutes, within which X will lie on 80% of days.

A First Course in Probability (10th Edition)

10th Edition

ISBN:9780134753119

Author:Sheldon Ross

Publisher:Sheldon Ross

Chapter1: Combinatorial Analysis

Section: Chapter Questions

Problem 1.1P: a. How many different 7-place license plates are possible if the first 2 places are for letters and...

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