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| Question 333211:  You are measuring the response of a new automobile braking system and are determining skid distance during panic braking.
 You are willing to accept an error of 2 feet.
 You choose to work at the 5% level of significance.
 From historical data, you know that the range of data for all skidding stops is about 24 feet
 Thank you!
 Answer by stanbon(75887)
      (Show Source): 
You can put this solution on YOUR website! You are measuring the response of a new automobile braking system and are determining skid distance during panic braking. You are willing to accept an error of 2 feet.
 You choose to work at the 5% level of significance.
 From historical data, you know that the range of data for all skidding stops is about 24 feet
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 Since the range is 24 ft, 6*sigma = 24.
 Therefore the standard deviation = 4
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 Sample size = [z*s/E]^2 = [1.96*4/2]^2 = 15.36
 Rounding up, n = 16.
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 Cheers,
 Stan H.
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