Answer:
0.9797
Explanation:
We have X = number of insects in the 25bgrams of butter
Then the legal limit of concentration in peanut butter = 30 fragments/ 100 grams
Then insect amount in 25 grams =
E(X) = 30/100 x 25
= 0.3 x 25
= 7.5 fragments of insects
Using the poisson function in Excel, the probability of at least 3 crunchy critters
1 - p(X<=2)
p(X<=2) = POISSON (2, 7.5, TRUE) = 0.020156715
1 - 0.020156715
= 0.9797