The space shuttle flight control system called Primary Avionics Software Set (PASS) uses four independent computers working in parallel. At each critical step, the computers “vote” to determine the appropriate step. The probability that a computer will ask for a roll to the left when a roll to the right is appropriate is 0.0001. Let X denote the number of computers that vote for a left roll when a right roll is appropriate. What are the mean and variance of X ?

Solution:

Step 1 of 2:

It is given that Primary Avionics Software Set ,the space shuttle flight control system uses 4 independent computers in parallel.

Also, it is given that 0.0001 is the probability that a computer will ask for a roll to the left when the right is appropriate.

The number of computers ask for a roll to the left when the right is appropriate is denoted by X.

Using this we need to find the mean and variance of X.