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The diameters of ball bearings are distributed normally. The mean diameter is 107 millimeters and the population standard deviation is 5 millimeters.

Find the probability that the diameter of a selected bearing is between 104 and 115 millimeters. Round your answer to four decimal places.


What is the notation?

User Piotr Jurkiewicz
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1 Answer

21 votes
21 votes

Answer:

0.6710

Explanation:

The diameters of ball bearings are distributed normally. The mean diameter is 107 millimeters and the population standard deviation is 5 millimeters.

Find the probability that the diameter of a selected bearing is between 104 and 115 millimeters. Round your answer to four decimal places.

We solve using z score formula

z = (x-μ)/σ, where

x is the raw score

μ is the population mean = 107 mm

σ is the population standard deviation = 5 mm

For x = 104 mm

z = 104 - 107/5

z = -0.6

Probability value from Z-Table:

P(x = 104) = 0.27425

For x = 115 mm

z = 115 - 107/5

z = 1.6

Probability value from Z-Table:

P(x = 115) = 0.9452

The probability that the diameter of a selected bearing is between 104 and 115 millimeters is calculated as:

P(x = 115) - P(x = 104)

0.9452 - 0.27425

= 0.67095

Approximately = 0.6710

User Wex
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3.3k points