Answer:
The probability of getting exactly two tails = 1/4
All the values greater than 1/4
or 3/4
Explanation:
In a flip of a coin the probability of getting a tail is 1/2. If this is denoted by p =1/2 then q= 1-p= 1-1/2= 1/2
and if we have number of trials n=2
Then the binomial distribution can be applied.
(p+q)ⁿ =(p+q)² = 2c0p⁰q2 + 2c1p¹q¹ + 2c2p²q⁰
We wish to find probability of flipping exactly two coins given by 2c2p²q⁰
= 2c2 (1/2)²(1/2)⁰
= 1/4
So the probability of getting exactly two tails = 1/4
The probability greater than 1/4 can be all the values from 2/4, 3/4 ------1
or it can be found by
1- 1/4 = 3/4
as the total probability is always equal to 1