Question

A manufacturer of envelopes knows that the weight of the envelopes weighing (i) 2 gm or more (ii) 2.1 gm or more, can be expected in a given packet of 1000 envelopes. [given P(0≤z≤1 )= 0.3413 and P(0≤z≤2)= 0.4772] { Ans. Approx.. 159 envelopes, 23 envelopes}