STATS question!

[tuckletoe]

Why are we using approximation here.
On average, 2 apples out of 15 are classified as being underweight. Find the probability that in a
random sample of 200 apples, the number of apples which are underweight is more than 21 and less
than 35.

 

[remz]

We are using approximation here because you will convert this binomial distribution into normal distribution. So when that happens, we apply contunity correction and hence approximation.

 

[zeebujha]

Why are we using approximation here.
On average, 2 apples out of 15 are classified as being underweight. Find the probability that in a
random sample of 200 apples, the number of apples which are underweight is more than 21 and less
than 35.

We have used the normal approximation for the binomial distribution as np>5 and nq>5
n=200
p=2/15
q=13/15