Question

Assuming distribution to be Poisson, the prob. that at most 5 defective bolts will be found in a box of 200 bolts, if it is known that 2% of such bolts are defective, is -

• A. e^–5
• B. e^–4 $\sum _ { \mathrm { i } = 1 } ^ { 4 } \frac { 4 ^ { \mathrm { i } } } { \mathrm { i } ! }$
• C. e^–4
• D. None of these

Answer 1

Answer: (C)

e^–4

Answer 2

p = $\frac { 2 } { 100 }$ , n = 200

m = np = 4

At most 5 defective = p (0) + p (1) + …. + p(5)

= e^–4