Example 7.3The production process for engine control housing units of a particular type has recently been modified. Prior to this modification, historical data had suggested that the distribution of hole diameters for bushings on the housings was normal with astandard deviation of 0.100 mm. It is believed that the modification has not affected the shape of the distribution or the standard deviation, but that the value of the mean diameter may have changed. A sample of 40 housing units is selected and holediameter is determined for each one, resulting in a sample mean diameter of 5.426 mm. Let's calculate a confidence interval for true average hole diameter using a confidence level of 90%. This requires that 100(1 - α) =which a = 10X and Za/2= 20.05= 1.645 (corresponding to a cumulative z-curve area of 0.9500). The desired interval is thenX, from0.100✓ 40With a reasonably high degree of confidence, we can say that 5.400 < μ< 5.452. This interval is rather narrow because of the small amount of variability in hole diameter (o = 0.100).5.426 +1.645= 5.426 ± 0.026 = (5.400, 5.452)

From given data we have : n=40, x=5.426, σ=0.100

Answered: The production process for engine…

MATLAB: An Introduction with Applications

6th Edition

ISBN:9781119256830

Author:Amos Gilat

Publisher:Amos Gilat

Chapter1: Starting With Matlab

Section: Chapter Questions

Problem 1P

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