8. (19 pts) Many veterans who bravely served in Iraq during Operation Enduring Freedom have developed symptoms of post-traumatic stress disorder (PTSD). A large study of returning veterans showed that 53% of the soldiers suffered from PTSD after serving in Iraq. A random sample of 200 veterans from Iraq were selected for additional research. Let X represent the number suffering from PTSD.

a. State the values of n and p for this binomial experiment. (2 pts.)

b. Compute the mean and standard deviation for X. Round to 2 decimal places. (5 pts.)

c. Verify whether or not the the distribution is approximately normally distributed ( 4 pts).

d. Compute the range of "usual" values for X. (4 pts.)

e. Would it be unusual to observe 75 soldiers suffering from PTSD? Why? (4 pts.)

I'm very confused on how to go about doing this. Any advice is appreciated. I'm using R Code for this.

In a sample of 1000 U.S. adults, 150 said they are very confident in the nutritional information on restaurant menus. Four U.S. adults are selected at random without replacement.

(a) Find the probability that all four adults are very confident in the nutritional information on restaurant menus.

(b) Find the probability that none of the four adults are very confident in the nutritional information on restaurant menus.

(c) Find the probability that at least one of the four adults is very confident in the nutritional information on restaurant menus.

(d) Which of the events can be considered unusual? Explain.

A good that takes up a very large percentage of the consumer's budget will tend to have

1. an elastic demand.

2. a perfectly elastic demand.

3. an inelastic demand.

4. an upward-sloping demand curve.

5. very many substitutes.