Question

QUESTION 21 Guidance Missile System. A missile guidance system has 5 fail-safe components. The probability of each falling is 0.05. Find the probability that Exactly 2 will fail. Use the table, not the formula QUESTION 22 A missile guidance system has 5 fail-safe components. The probability of each failing is 0.05. Find the probability that More than 2 will fail.

Answer 1

21)

Answer)

As there are fixed number of trials and probability of each and every trial is same and independent of each other

Here we need to use the binomial formula

P(r) = ncr*(p^r)*(1-p)^n-r

Ncr = n!/(r!*(n-r)!)

N! = N*n-1*n-2*n-3*n-4*n-5........till 1

For example 5! = 5*4*3*2*1

Special case is 0! = 1

P = probability of single trial = 0.05

N = number of trials = 5

R = desired success = exactly 2

P(2) = 5c2*(0.05^2)*(1-0.95)^5-2 = 0.021434375

You can look into binomial table

For n = 5 and x = 2

B)

P(x>2)

= P(3) + p(4) + p(5)

= 0.001158125