Practice FT2 Q10 - Looking for a detailed, worked solution with theoretical explanation

The Aromalicious tea Company produces packets of tea which are supposed to contain 480 grams. It is found that the packing machine delivers an amount of tea which is approximately normally distributed with mean / grams and standard deviation 6 grams. Here the mean / can be adjusted by turning a dial on the machine but the standard deviation cannot be changed. a) To allow for a margin of error, the machine operator sets / = 485, what proportion of the packets will be under 480 grams? Give your answer to part a to four decimal places, such as 0 . 1234 proportion of packets under 480 grams = b) In order to make the proportion of underweight packets at most 34 per 10, 000, what setting should be used for /? Enter your value for mu in the box below. Give your answer to part b to two decimal places, such as 3 . 14 H = c) Explain your method in (b) in the below below part (d). (Note this is will be used to award partial marks if your answer to (b) is wrong. d) Should the continuity correction be used in this question? Explain why or why not in the box below. Insert explanation Standard normal probabilities P(Z