In the U.S, novice COVID-19 infects one of every 1,000 people. There is a good, but not perfect, test for Covid-19. If the person has covid, the test comes back positive 99% of the time. On the other hand, the test also produces some false positives( you test positive even though you don't have Covid). if the person is free of covid, the probability the test come back positive is 2%.. Given that you tested positive for covid, what is the probability that you have covid?

a. 4.72%

b. 2.68%

c. 1.26%

d. 11%

A recent survey by the VTDept. of Transportation revealed that 60% of the vehicles traveling on US 89, which has a 65 mile per hour speed limit, were speeding. If you were to select 10 vehicles at random and recorded their speed, the standard deviation of the distribution is______