Which of the following is true about the t-distribution?
a. they are uni-modal and symmetric.
b. regardless of the degrees of freedom it has fatter tails than the normal model.
c. as the degrees of freedom increase, the t-curve looks more and more like the normal.
d. all of the above.

D) All options are True

Step-by-step explanation:

A) t-distribution are symmetrical and uni-modal like Normal the Normal distribution.

B) Normal distribution is said to lack 'uncertainty'. Because of this, its more concentrated on values near the mean, while t-student distributions have more spread values and, as a result, fatter tails.

C) This is true as well, the higher the degrees of freedom, the less uncertainty the t-student has, and they will become as a result, more and more similar to the Normal distribution.

All options are True, so option D is the answer.

answer: 230 miles ( vote ! )

step-by-step explanation:

180.39 minus 17.99 equals 162.4

then divide 162.4 by .80 to get 230