Question

A weighted coin has probability 0.7 of getting heads, and 0.3 of getting a tails. If the coin is tossed 6 times, what is the probability of getting at least 4 heads? What is the probability of getting less than 4 heads?

Answer 1

Here a weighted coin has probability 0.7 of getting head,

and 0.3 of getting a tails

Thus

p=0.7 and q=0.3

If the coin is tossed 6 times

so n=6

Here tossing a coin is independent event

Hence This is Binomial Distribution with parameter n=6 and p=0.7

The probability of getting at least 4 heads is,

Thus  probability of getting at least 4 heads is 0.7443

Now the probability of getting less than 4 heads is,

Thus the probability of getting less than 4 heads is 0.2557