The traffic dept knows that 80% of the motorists wear their safety belts. A total of n=5 motorists are stopped at a road block. Let x=number of motorists who wear their safety belts, p=x/n=sample proportion of the motorists who wear their safety belts
a) Find the probability that only the first and the last motorist (in the sample of 5) wear their safety belts.
b) The probability that 3 out of the 5 motorists wear a safety belt is:
c)The probability that only 1 out of the 5 motorists does not wear a safety belt is:
d) The standard deviation of x, the number of motorists who wear a safety belt is:
e) The standard deviation of p, the proportion of motorists who wear a safety belt is:
f) During the first road block it was found that 3 out of 5 motorists wore their safety belts. The sampling error of p is: