Medical billing errors and fraud are on the rise. According to onestudy, 4 out of 5 times, the medical bills received by patients are not right. Complete parts(a) through(d) below.

a. If a sample of 9 medical bills isselected, what is the probability that exactly 0 bills will containerrors?

The probability is

.

(Type an integer or decimal rounded to four decimal places asneeded.)

b. If a sample of 9 medical bills isselected, what is the probability that exactly 6 bills will containerrors?

The probability is

.

(Type an integer or decimal rounded to four decimal places asneeded.)

c. If a sample of 9 medical bills isselected, what is the probability that more than 7 bills will containerrors?

The probability is

.

(Type an integer or decimal rounded to four decimal places asneeded.)

d. What are the mean and standard deviation of the probabilitydistribution?

The mean is

and the standard deviation is