Probability and Statistics Question

Question

There are 45 green and 55 red Christmas ornaments in a box that you cannot see into. Imagine that you have to choose an ornament and then place it back into the box.

a) What is the probability of choosing a red ornament?
b) What is the probability of choosing a green, and then another green ornament?
c) What is the probability of choosing a green and then a red ornament?
d) What is the probability of choosing a red, and then another red ornament?

Answer 1

Hi Christopher,

 

 

You are dealing with choosing an object with replacement

(a) R = choosing a red ornament

P(R) = 55/(45 + 55) = 55/100 = 11/20 or 0.55

       

(b) G =  choosing a green ornament

P(G and then G) = P(G)*P(G) 

                        =(45/100)*(45/100) =81/400 or 0.2025

 

(c) P(G and then R) = P(G)P(R) 

                             =(45/100)*(55/100) =99/400 or 0.2475

 

(d) P(R and then R) = P(R)*P(R)
                             =(55/100)*(55/100) =121/400 or 0.3025