Question

If you roll a die 100 times, what is the approximate probability that you will roll between 9 and 16 ones, inclusive? (Round your answer to two decimal places.) HINT [See Example 4.]

Answer 1

Answer: 0.47

Explanation:

Given that

n = 100, probability of rolling 1 = 1/6

binomial approximation

np = 100 ( 1/6) = 16.667

standard deviation = √ 100 × 1/6 ×5/6 = 3.7627

P ( 9 ≤ X ≤ 16 )

= P ( 8.5 < X < 16.5 )

so,

= P ((8.5 - 16.6667) / 3.7627 < Z < (16.5 - 16.6667) / 3.7627

= P ( -2.17 < Z < -0.04 )

= 0.484 - 0.015

= 0.47

Therefore the approximate probability that you will roll between 9 and 16 ones is 0.47