1. In a survey, 85% of the voters support a particular referendum. If 40 voters are chosen at random, and X is the number of voters that support this referendum, find the standard deviation of X.
2. In a survey, 55% of the voters support a particular referendum. If 40 voters are chosen at random, and X is the number of voters that support this referendum, find the mean and variance of X.
3. A school is sending 11 children to a camp. If 20% of the children in the school are first graders, and the 8 children are selected at random, what is the mean and variance of the number of first graders chosen?
4. If 1.5% of the bolts made by an automotive factory are defective, what is the probability that in a shipment of 200 bolts, there are 6 defective bolts?
6. Draw a graph showing the probability distribution for the sample space for tossing four coins.