Answered

Get the answers you've been looking for with the help of IDNLearn.com's expert community. Our platform offers reliable and detailed answers, ensuring you have the information you need.

Installation of certain hardware takes a random amount of time. The installation times form a normally distributed distribution with a standard deviation 5 minutes and a mean of 45 minutes. A computer technician installs the hardware on 31 different computers. You are interested to find the probability that the mean installation time for the 31 computers is less than 43 minutes.

Select the most appropriate item that pertains to the problem.

a. z=-0.4
b. none of these
c. z=-2.23
d. z=2.23

And,
What is the probability that the mean installation time for 31 computers is less than 43 minutes?

a. 0.400
b. 0.345
c. none of these
d. 0.0129
e. 0.987

Sagot :

Fichohidn

The most appropriate values are:

z = - 2.23

The corresponding probability is : 0.01297

Mean, μ = 45

Standard deviation, σ = 5

Sample size, n = 31

The standard score, Z ; Since distribution is normal is obtained thus;

Z= (x - μ) ÷ (σ/√n)

For, x = 43

Z = (43 - 45) ÷ (5/√31)

Z = - 2.227

The probability :

Using the standard normal distribution table:

P(Z < - 2.227)

P = 0.01297

Hence, Z = - 2.23

P(x ≤ 43) = 0.0129



Learn more on Z probability :

https://brainly.com/question/4555552

We appreciate your contributions to this forum. Don't forget to check back for the latest answers. Keep asking, answering, and sharing useful information. IDNLearn.com has the solutions you’re looking for. Thanks for visiting, and see you next time for more reliable information.