Question

The amount of pyridoxine (in grams) in a multiple vitamin is normally distributed with  = 110 grams and  = 25 grams. What is the probability that a randomly selected vitamin will contain less than 100 grams or more than 120 grams of pyridoxine

Answer 1

Explanation:

You calculate z-score of both

z-score = (x-mean)/SD

for 100; (100-110)/25 = -0.4

for 120; (120-110)/25 = 0.4

Probability we want to calculate is;

P(z<-0.4) or P(z>0.4)

We find the individual probabilities using z-score table and add up both together;

P(-0.4<z<0.4) = 0.31084