Question 7.29

7.29 Plant capacity.

A leading company chemically treats its product before packaging. The company monitors the weight of product per hour that each machine treats.

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An SRS of 90 hours of production data for a particular machine is collected. The measured variable is in pounds.

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  1. Describe the distribution of pounds treated using graphical methods. Is it appropriate to analyze these data using distribution methods? Explain.
  2. Calculate the mean, standard deviation, standard error, and margin of error for 90% confidence.
  3. Report the 90% confidence interval for the mean pounds treated per hour by this particular machine.
  4. Test whether these data provide evidence that the mean pounds of product treated in one hour is greater than 33,000. Use a significance level of 5%, and state your hypotheses, the -value, and your conclusion.

7.29

(a) The data are slightly left-skewed but because , we can still use the procedures. (b) The margin of error for 90% is 1817.5. (c) (33,470.7, 37,105.7).
(d) The data are significant at the 5% level, and there is evidence that the mean pounds of product treated in 1 hour is greater than 33,000.