Answer to Question #77084 in Statistics and Probability for Robert

Question

A quality audit of a bottling company showed the number of defective batches outside of the specification limits for a particular oil product. The grouped data shown in the table below indicates the number of defective items per unit of measurement.

CLASS LIMITS
f CUM<f CLASS MARK(X)
Xf X- X ̅ (X− X ̅)2
(X−X ̅)2 f 20-<25 1 25-<30 2 30-<35 8 35-<40 5 40-<45 3 45-<50 1 TOTAL


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3.1.1 Complete the table data under the given columns. (5)
3.1.2 Calculate the mean value. (5)
3.1.3 Draw the cumulative frequency polygon and then use your graph to determine the median. (5)
3.1.4 Use the values from 3.1.2 and 3.1.3 to comment on the nature of the distribution. Give a reason for your answer