Question

A design engineer wants to see if the service life of a halogen headlamp is within control. The service life is normally distributed with a mean of 500 hours and a stastandard deviation of 20 hours. What is the sample mean service life for sample 2

Answer 1

Complete Question

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Answer:

1

The correct option is C

2

The correct option is C

Explanation:

From the table give

The sample sample size is n = 4

Generally the sample mean of the service life for sample 2 is mathematically represented as

`\= x_2 = (525 + 515 + 505 + 515)/(4)`

`\= x_2 = 515 \ hours`

Generally the sample mean of the service life for sample 1 is mathematically represented as

`\= x_1 = (495 + 500 + 505+ 500)/(4)`

`\= x_1 = 500 \ hours`

Generally the sample mean of the service life for sample 3 is mathematically represented as

`\= x_3 = (470 + 480 + 460+ 470)/(4)`

`\= x_3 = 470\ hours`

Generally the mean of the sampling distribution of sample mean is mathematically represented as

`\mu_(\= x) = (\= x_ 1 +\= x_ 2+\= x_ 3 )/(3)`

=>
`\mu_(\= x) = (500 + 515+470 )/(3)`

=>
`\mu_(\= x) =495 \ hours`