SOLUTION: A machine that manufactures automobile pistons is estimated to produce a defective piston 3% of the time.
Suppose that this estimate is correct and that a random sample of 90 pist
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-> SOLUTION: A machine that manufactures automobile pistons is estimated to produce a defective piston 3% of the time.
Suppose that this estimate is correct and that a random sample of 90 pist
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Question 333849: A machine that manufactures automobile pistons is estimated to produce a defective piston 3% of the time.
Suppose that this estimate is correct and that a random sample of 90 pistons produced by this machine is taken.
Estimate the number of pistons in the sample that are defective by giving the mean of the relevant distribution
(that is, the expectation of the relevant random variable).
Do not round your response. Quantify the uncertainty of your estimate by giving the standard deviation of the distribution.
Round your response to at least three decimal places
I am trying to work this situation out using Excel, but am confused about how to calculate the standard dev
You can put this solution on YOUR website! Let X =number of defectives in the sample
Let n= sample size
let =population defective rate
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Since there are two outcomes to each event (each piston is either defective or not) and the we assume that the outcomes from piston to piston are independent and the probability of being defective is the same for each piston, this would define a binomial experiment. in other words x~binomial (n,)
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If n =90 and (you give this information)
--- =the expected value of x = n* = 90*0.03=2.70 defective pistons
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variance of x==90*0.03*0.97=2.619
standard deviation of x ==
