It is known that 80% of all brand A zip drives work in a satisfactory manner throughout the warranty period (are “successes”). Suppose that n
10 drives are randomly selected.

Let X
the number of successes in the sample. The statistic X/n is the sample proportion (fraction) of successes.

Obtain the sampling distribution of this statistic. [Hint: One possible value of X/n is .3, corresponding to X
3. What is the probability of this value (what kind of random variable is X)?]