Question

The probability of a product being defective from a certain company is 2%. If 100 products are tested, calculate the following:
a. The probability that 2 products are defective is
b. The probability that at most 4 are defective is
c. The expected number of defective products is

Answer 1

n=100, p= 0.02

(a) $P(=2)$

The Excel formula, =BINOM.DIST(2,100,0.02,FALSE) yields 0.273414

Thus $P(=2)=0.273414$

(b) $P(\le4)$

The Excel formula

BINOM.DIST(4,100,0.02,TRUE) yields

$P(\le4)=0.94917$

(c) Expectation

Expectation is given by $n×p= 100×0.02=2$