1. The scores on a certain test follows a normal distribution with mean 70 and standard deviation 5. What is the probability that a student will receive a score between 75 and 85?

2.The American Red Cross says that about 11% of the U.S. population has Type B blood. A blood drive is being held at your school. What is the probability thatexactly 2of the first 20 blood donors have Type B blood?

3.According to the IRS, the average length of time for an individual to complete an IRS Form 1040 is 10.53 hours and the standard deviation of 2 hours. What is the probability that 36 taxpayers if randomly selected finished their Form 1040s in an average of less than 12 hours?

4.Assume the following probabilities for two events, and :

() = 0.50, () = 0.70, ( ) = 0.85

Are the events, and , independent in this situation?