Question

PLEASE ONLY USE EXCEL AND SHOW FORMULAS W/THE ARGUMENTS.

Consider the probability that no more than 98 out of 125 DVDs will work correctly. Assume the probability that a given DVD will work correctly is 51%

.

Specify whether the normal curve can be used as an approximation to the binomial probability by verifying the necessary conditions.

PLEASE ONLY USE EXCEL AND SHOW FORMULAS W/THE ARGUMENTS. THANK YOU!

Answer 1

Here n = 125

and p = 0.51

Let's check the following conditions that  the normal curve can be used as an approximation to the binomial probability

1) n*p >= 5

2) n*(1-p) > 5

1) n*p = 125*0.51 = 63.75 > 5

2) n*(1-p) = 125*0.49 = 61.25 > 5

Here both the conditions are satisfied,

So we can use normal curve can be used as an approximation to the binomial probability

Here we want to find ,the probability that no more than 98 out of 125 DVDs will work correctly.

Mathematically, P( X <= 98 )

Let's make continuity correction.

P( X <= 98 +0.5) = P( X < 98.5 )

Let's use excel:

The forrmulae used on the above excel-sheet are as follows: