5) The product is sold in packets whose masses are normally distributes with mean of 1.42 kg and a standard deviation of 0.025 kg.

(1) Find the probability that the mass of a packet, selected at random, lies between 1.37 kg and 1.45 kg

1 answer

Z = (score-mean)/SD

Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportion/probability between the two Z scores.