a study of the amount of time it takes a mechanic to rebuild the transmission for a 2010 chevrolet colorado shows that the mean is 8.4 hours and the standard deviation is 1.8 hours. if 40 mechanics are randomly selected, find the probability that their mean rebuild time is less than 8.9 hours. round to four decimal place

The answer is 0.9599.

Explanation:

mu (sample) = mu = 8.4

s.d. (sample) = 1.8/ sq. rt. 40

P( greater than 8.1) = (8.9-8.4)/(1.8/ sq. rt. 40)

Let x be the mean time for the 40 mechanics

Standardize the mechanics: (8.9-8.4)/(1.8/ sq. rt. 40) = 1.75 = Z

P( x > 8.9) = P(Z > 1.75), this means the area to the right of Z = 1.75.

Then you need to look in the table of the Normal distribution, Z(1.75) =0.9599

8.5

explanation:

it was really good but i wish there would be more humor.

answer

the most effective ways of dealing with and reducing stress could be; listening to relaxing music, yoga, aromatherapy and meditation

explanation

when stress is effectively managed, it the effect stress has on a person’s life so they can be productive, happy and healthier. it is vital to identify the source of stress to be able to manage it. some stress management tips are keeping a positive attitude, practicing relaxation techniques, exercising regularly and eating healthier.