In each case, determine whether the situation calls for a

discrete or continuous random variable and explain
your answer. Please help!

a. The description of the number of children in a family
selected at random from families in Ft. Wayne, Indiana

b. The net worth of an average person in the United
States

c. The cholesterol level of individuals having heart
attacks between the ages of 35 and 50

d. The sum showing after a roll of two dice

In each case, consider what you know about the distribution

and then explain why you would expect it to be
or not to be normally distributed.

I am really having a hard time understanding this. Any help would be great.

a. The wealth of the parents of students attending your
school

b. The values that a group of fourth-grade students
would give for the length of a segment that they
measured with a ruler

c. The SAT or ACT examination scores in mathematics
for students who were in your high school
graduation class

d. The weights of all incoming freshman students at
your school

A discrete variable can only take on certain values. For example 4 children or 5 in a family but not 4.3782

Net worth can be any number at all though so is continuous.

By the way read at

http://www.stats.gla.ac.uk/steps/glossary/probability_distributions.html

Normal distributions model (some) continuous random variables. Strictly, a Normal random variable should be capable of assuming any value on the real line, though this requirement is often waived in practice. For example, height at a given age for a given gender in a given racial group is adequately described by a Normal random variable even though heights must be positive. (example wealth of parents normal distribution about mean (average)

(For discrete variable Poisson distribution is used.)(example SAT scores are discrete)

By the way the fourth graders would probably not use fractions with their ruler, so only discrete whole numbers would be given.

So normal distributed is when you can not have a decimal such as 4.3782 (children example) & not normal distributed would be when it is ok to have a decimal

That is pretty much the idea, but really discrete means only certain values. For example if half values were allowed but not others like 1/4 and 3/4 it would still be discrete, a finite number of values allowed.