Question

The voltage in a certain circuit is a normal random variable with mean 120 and standard...

The voltage in a certain circuit is a normal random variable with mean 120 and standard deviation 5. Sensitive equipment will be damaged if the voltage is not between 112 and 128. What is the probability that the equipment will be damaged?

Homework Answers

Answer #1

Solution:

Given that,

mean =  = 120

standard deviation =  = 5

p ( 112 < x < 128 )

= p (112 - 120 / 5) < ( x -  / ) < ( 128-120/5)

= p ( - 8 / 5 < z < 8 / 5 )

= p (- 1.6<z <1.6 )

= p (z < 1.6 ) - p ( z < - 1.6 )

Using z table

= 0.9452 - 0.0548

= 0.8904

Probability = 0.8904

Know the answer?
Your Answer:

Post as a guest

Your Name:

What's your source?

Earn Coins

Coins can be redeemed for fabulous gifts.

Not the answer you're looking for?
Ask your own homework help question
Similar Questions
A certain population has an income distribution given by a normal random variable whose mean is...
A certain population has an income distribution given by a normal random variable whose mean is $35000 and whose standard deviation is $7500. A. What is the probability that a randomly selected person has an income of at least $35000?
Let X distributed as a Normal random variable with a mean of 15 and a standard...
Let X distributed as a Normal random variable with a mean of 15 and a standard deviation of 3. A) What is the probability associated with an outcome between (12, 18)? B) What is the probability associated with an outcome between (9, 21)? C) What is the probability associated with an outcome between (12, 21)?
Let X distributed as a Normal random variable with a mean of 15 and a standard...
Let X distributed as a Normal random variable with a mean of 15 and a standard deviation of 3. A) What is the probability associated with an outcome between (12, 18)? (Example answer ##%) B) What is the probability associated with an outcome between (9, 21)? (Example answer ##%) C) What is the probability associated with an outcome between (12, 21)? (Example answer ##.#%)
A normal random variable x has an unknown mean and standard deviation. The probability that x...
A normal random variable x has an unknown mean and standard deviation. The probability that x exceeds 4 is 0.975, and the probability that x exceeds 5 is 0.95. Find μ and σ.
A random variable is normally distributed with a mean of μ=50 and a standard deviation of...
A random variable is normally distributed with a mean of μ=50 and a standard deviation of σ = 5. a) Sketch a normal curve for the probability density function. Label the horizontal axis with values of 35, 40, 45, 50, 55, 60, and 65. b) What is the probability the random variable will assume a value between 45 and 55? c) What is the probability the random variable will assume a value between 40 and 60? d) Draw a graph...
A standard normal random variable is a random variable that is normally distributed with mean equal...
A standard normal random variable is a random variable that is normally distributed with mean equal to 1 and standard deviation equal to 1. Group of answer choices True False
Given that z is a standard normal random variable, compute the following probabilities.
Given that z is a standard normal random variable, compute the following probabilities. (Round your answers to four decimal places.)(a)P(0 ≤ z ≤ 0.86)(b)P(−1.54 ≤ z ≤ 0)(c)P(z > 0.44)(d)P(z ≥ −0.22)(e)P(z < 1.30)(f)P(z ≤ −0.75)Also..A population has a mean of 128 and a standard deviation of 32. Suppose a sample of size 64 is selected andxis used to estimate μ. (Round your answers to four decimal places.)(a)What is the probability that the sample mean will be within ±5 of...
Let z be a normal random variable with mean 0 and standard deviation 1. What is...
Let z be a normal random variable with mean 0 and standard deviation 1. What is P(-2.25 < z < -1.1)? a 0.3643 b 0.8643 c 0.1235 d 0.4878 e 0.5000 Let zbe a normal random variable with mean 0 and standard deviation 1. The 50thpercentile of zis ____________. a 0.6700 b -1.254 c 0.0000 d 1.2800 e 0.5000 Let zbe a normal random variable with mean 0 and standard deviation 1. The 75thpercentile of zis ____________. a 0.6700 b...
A random variable is normally distributed with a mean of μ = 60 and a standard...
A random variable is normally distributed with a mean of μ = 60 and a standard deviation of σ = 5. What is the probability the random variable will assume a value between 45 and 75? (Round your answer to three decimal places.)
A continuous random variable Z follows standard normal distribution. a) What is the mean of Z?...
A continuous random variable Z follows standard normal distribution. a) What is the mean of Z? b) What is the standard deviation of Z? c) Z=(x-10)/5 What is the distribution of X ?