=+b. Suppose that these capacitors are shipped in batches of size 20. Let x denote the number of capacitors in a batch that conform to specification.

Provided that capacitances of successive capacitors are independent of one another, what kind of distribution does x have? In the long run, in what proportion of batches will at least 19 of the 20 capacitors conform to specifications? Hint: Think of a capacitor that conforms to specification as a “success,” so x is the number of successes in the batch.