In one flip of 10 unbiased coins, what is the probability of getting a result as extreme or more extreme than 8 heads?
A) 0.0547
B) 0.1094
C) 0.0020
D) 1.0000

Question

Quizplus · Accepted Answer

To find the probability of getting 8, 9 or 10 heads, we need to add up the probabilities of each of these scenarios. 
The probability of getting exactly 8 heads is 10C8 * (1/2)^10 = 0.0439. 
The probability of getting exactly 9 heads is 10C9 * (1/2)^10 = 0.0098. 
The probability of getting exactly 10 heads is 10C10 * (1/2)^10 = 0.00098. 
So, the probability of getting a result as extreme or more extreme than 8 heads is: 
0.0439 + 0.0098 + 0.00098 = 0.05468, which is closest to answer choice B, 0.1094 (rounded to four decimal places).

In One Flip of 10 Unbiased Coins, What Is the Probability