NCERT Class XII Mathematics Chapter - - Solutions
© examsnet.com
Question : 60
Total: 101
Find the mean number of heads in three tosses of a fair coin.
Solution:
Sample space = {HHH, HHT, HTH, THH, HTT, THT, TTH, TTT}.
Let X denotes the random variable, which represents the number of heads in three tosses of a fair coin.
∴ X can assumes values 0, 1, 2 and 3.
∴ P ( X = 0 ) =
P ( X = 1 ) =
P ( X = 2 ) =
P ( X = 3 ) =
∴ Mean = E(X) = ∑X P(X) = ( 0 ×
) + ( 1 ×
) + ( 2 ×
) + ( 3 ×
) =
Let X denotes the random variable, which represents the number of heads in three tosses of a fair coin.
∴ X can assumes values 0, 1, 2 and 3.
| X | 0 | 1 | 2 | 3 | ||||||||
| P(X) | | | | |
© examsnet.com
Go to Question: