There are 200 lathes of the same type in a workshop. Assuming that the starting probability of each lathe is 0.7 and the switches are independent of each other, the power consumption of each lathe whe

There are 200 lathes of the same type in a workshop. Assuming that the starting probability of each lathe is 0.7 and the switches are independent of each other, the power consumption of each lathe when starting is 15 kW. Just try it. Set x lathe, X~B(200, 0.7);

EX = 200 * 0.7 = 140；

DX = 200 * 0.7 * 0.3 = 42

p {(X-EX)/sqrt(DX)& lt； = x} = f(x) (f(x) is a standard normal function)

If the yield meets the probability of at least 95%, then f(x)=0.95, from which the size of x can be calculated (look up the normal distribution table).

X is between 1.64 and 1.65.

X = T at this time (t is known at this time);

x- 140/sqrt(42)& lt； = T；

x = 140+T * sqrt(42)；

X = 15 1

The power consumption is151*15 = 2265.