Defective transistors; from past experience a company has found that in cartons of transistors, 92% contain no defective transistor, 3% contain one defective transistors, 3% contain two defective transistor, and 2% three defective transistors. find the mean, variance and standard deviation for the defective transistors. about how many extra transistors per day would the company need to replace the defective ones if it used 10 cartons per day?