# Math Help - Probability Question

1. ## Probability Question

Question :
The probability of error in the transmission of a bit over a communication channel is $p = 10^{-4}$. What is the probability of more than three errors in transmitting a block of 1,000 bits?

2. It's a binomial distribution. $_{1000}C_x (10^{-4})^x (1 - 10^{-4})^{1000-x}$

So P(X>3) = 1 - P(X <=3)

where P(X <= 3) = P(X=0) + P(X=1) + P(X=2) + P(X=3)

3. ## Is this correct?

Originally Posted by statmajor
It's a binomial distribution. $_{1000}C_x (10^{-4})^x (1 - 10^{-4})^{1000-x}$

So P(X>3) = 1 - P(X <=3)

where P(X <= 3) = P(X=0) + P(X=1) + P(X=2) + P(X=3)

This is what i am getting

P(X>3) = -0.00015
...............Please let me know if it is correct or no????

4. Originally Posted by zorro
This is what i am getting

P(X>3) = -0.00015...............Please let me know if it is correct or no????
Not correct. For starters, a probability cannot be negative. Please show how you got this answer.