Which of the following is true? (CAN select all at once or one at once, it does not matter which or how many answer choices you select, as long as it is accurate, of course).

a.A parameter is generally a known random variable.

b.A parameter is generally a fixed unknown value.

c.The purpose of a statistic is to estimate the value of a parameter.

d.The purpose of a parameter is to estimate the value of a statistic.

e.If we are taking a census, we may know the value of the parameter.

f.A statistic is generally a fixed known value.

g.A parameter is generally a fixed known value.

h.A statistic is generally a fixed random variable.

i.A statistic is generally a known random variable.