A shop foreman found that it takes 40 minutes on average to complete a
specific task. Given that the standard deviation for this task is 6 minutes
and the times for completing this task are normally distributed, what is
the probability that on any given day it will take between 34 and 44
minutes to complete the task?

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Using the normal distribution, it is found that there is a 0.5899 = 58.99% probability that on any given day it will take between 34 and 44  minutes to complete the task.

In a normal distribution with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the z-score of a measure X is given by:

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

  • It measures how many standard deviations the measure is from the mean.  
  • After finding the z-score, we look at the z-score table and find the p-value associated with this z-score, which is the percentile of X.

In this problem:

  • Mean of 40 minutes, hence [tex]\mu = 40[/tex].
  • Standard deviation of 6 minutes, hence [tex]\sigma = 6[/tex].

The probability that on any given day it will take between 34 and 44  minutes to complete the task is the p-value of Z when X = 44 subtracted by the p-value of Z when X = 34, hence:

X = 44:

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]Z = \frac{44 - 40}{6}[/tex]

[tex]Z = 0.67[/tex]

[tex]Z = 0.67[/tex] has a p-value of 0.7486

X = 34:

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]Z = \frac{34 - 40}{6}[/tex]

[tex]Z = -1[/tex]

[tex]Z = -1[/tex] has a p-value of 0.1587

0.7486 - 0.1587 = 0.5899.

0.5899 = 58.99% probability that on any given day it will take between 34 and 44  minutes to complete the task.

A similar problem is given at https://brainly.com/question/24663213