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In: Statistics and Probability

In a manufacturing process a random sample of 36 bolts manufactured has a mean length of...

In a manufacturing process a random sample of 36 bolts manufactured has a mean length of 3 inches with a standard deviation of .3 inches. What is the 99% confidence interval for the true mean length of the bolt?

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Expert Solution

Solution :

Given that,

= 3

= 0.3

n = 36

At 99% confidence level the z is ,

  = 1 - 99% = 1 - 0.99 = 0.01

/ 2 = 0.01 / 2 = 0.005

Z/2 = Z0.005 = 2.576

Margin of error = E = Z/2* ( /n)

= 2.576 * (0.3 / 36)

= 0.1288

At 99% confidence interval estimate of the population mean is,

- E < < + E

3 - 0.1288 < < 3 + 0.1288

2.8712< < 3.1288

(2.8712 ,  3.1288 )

orchestra answered 2 years ago
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