# Don't know what formula to use...

• November 18th 2008, 07:14 AM
vedmachka
Don't know what formula to use...

It has been estimated that about 30% of frozen chicken contain enough salmonella bacteria to cause illness if improperly cooked. A consumer purchases 15 frozen chickens. What is the probability that the consumer will have less than 3 contaminated chickens? Round to 3 decimal places.

• November 18th 2008, 07:19 AM
Jhevon
Quote:

Originally Posted by vedmachka

It has been estimated that about 30% of frozen chicken contain enough salmonella bacteria to cause illness if improperly cooked. A consumer purchases 15 frozen chickens. What is the probability that the consumer will have less than 3 contaminated chickens? Round to 3 decimal places.

Use the binomial distribution.

$n = 15$, $p = 0.3 \implies q = 0.7$. you want $P(X < 3) = P(0) + P(1) + P(2)$
• November 18th 2008, 07:22 AM
vedmachka
Sorry...
Thank you so much for the formula, but I don't know how to solve that.(Crying)
• November 18th 2008, 07:35 AM
Jhevon
Quote:

Originally Posted by vedmachka
Thank you so much for the formula, but I don't know how to solve that.(Crying)

i told you the formula and gave you the parts, it is just plug and chug from here. where are you stuck?

see post #2 here

and here

and here

and post #34 here