fair die rolled six times. '6' is considered success.......

Question

A fair die is rolled five times. A "6" is considered a success. Find the probability of four successes. Use the binomial probability formula.

 

Need work shown so i can understand correctly.

Answer 1

Hi Evan,

 

   A fair die is rolled five times. A "6" is considered a success. Find the probability of four successes. Use the binomial probability formula.

 

A fair die has six sides.  The probability of rolling a six each time the die is rolled is 1/6 (this is the success).

 

The probability of not rolling a six is 1-1/6= 5/6 (not a success).

 

B(n,p)=B(5,1/6)     Since the die is rolled five times, you have   P(X=4)= ₅C₄ (1/6)⁴(5/6)^5-4

                                                                                                    =₅C₄ (1/6)⁴(5/6)¹

                                                                                                    = 5 (1/1296)(5/6)

                                                                                                     = 0.003215

If you use a TI-84, binompdf(5,1/6,4)=0.003215

 

Hope this helps you understand the process.

THINK MATH!!