A silicon integrated circuit chip contains 5000 ostensibly identical transistors. Measurements are made of the current gain of each transistor. The measurements have a mean of 20.0 and a standard...

A silicon integrated circuit chip contains 5000 ostensibly identical transistors. Measurements are made of the current gain of each transistor. The measurements have a

mean of 20.0 and a standard deviation of 1.5. The probability distribution of the measurements is Gaussian.

(a) Write down an expression for the number of transistors on the chip that have a

current gain between 19.5 and 20.5.

(b) Show that this number of transistors with a current gain between 19.5 and 20.5

is approximately 1300.

(c) Calculate the number of transistors that have a current gain of 17 or more (this

is the minimum current gain necessary for a transistor to be able to drive the

succeeding stage of the circuit in which the chip is used).