A die is a specialized tool used in manufacturing industries

A die is a specialized tool used in manufacturing industries to cut or shape material mostly using a press. Products made with dies range from simple paper clips to complex pieces used in advanced technology.
An article reported that, in a study of a particular wafer inspection process, 356 dies were examined by an inspection probe and 159 of these passed inspection. What is the estimated proportion of wafers that passed inspection? (Round your answers to three decimal places.) ________________
Assuming a stable process, calculate a 95% (two-sided) confidence interval for the proportion of all dies that pass the probe. (Round your answers to three decimal places.)
95%CI

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Solution

A die is a specialized tool used in manufacturing industries to cut or shape material mostly using a press. Products made with dies range from simple paper clips to complex pieces used in advanced technology.
An article reported that, in a study of a particular wafer inspection process, 356 dies were examined by an inspection probe and 159 of these passed inspection.

Confidence Interval Estimate for the Proportion

Data

Sample Size

356

Number of Successes

159

Confidence Level

95%

Intermediate Calculations

Sample Proportion=159/356=

0.447

Z Value

1.9600

Standard Error of the Proportion=sqrt(0.447*0.553/356)=

0.0263

Interval Half Width = 0.0263*1.96=

0.0515

Confidence Interval

Interval Lower Limit=0.447-0.0515=

0.396

Interval Upper Limit=0.447+0.0515=

0.499

What is the estimated proportion of wafers that passed inspection? (Round your answers to three decimal places.) = 0.447

Assuming a stable process, calculate a 95% (two-sided) confidence interval for the proportion of all dies that pass the probe. (Round your answers to three decimal places.)
95%CI = (0.396, 0.499)