Answered: TREKLAIR bulbs have an average lifespan…

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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Related questions

Question

TREKLAIR bulbs have an average lifespan of
800 hours with a variance of 1,600 hours2 .This duration of
life has a normal distribution. Find the probability that a
bulb lasts between 778 and 834 hours.

Features Features Normal distribution is characterized by two parameters, mean (µ) and standard deviation (σ). When graphed, the mean represents the center of the bell curve and the graph is perfectly symmetric about the center. The mean, median, and mode are all equal for a normal distribution. The standard deviation measures the data's spread from the center. The higher the standard deviation, the more the data is spread out and the flatter the bell curve looks. Variance is another commonly used measure of the spread of the distribution and is equal to the square of the standard deviation.

Expert Solution

Step 1: Introducing the given information

Mean( $mu$ ) = 800

Variance ( $sigma squared$ ) = 1600

Standard deviation( $sigma$ ) = $square root of V a r a i n c e left parenthesis sigma squared right parenthesis end root equals square root of 1600 space$ = 40

X~N( $mu equals 800 comma sigma equals 40 right parenthesis$