7. which statement(s) is/are correct about the t distribution?
a. mean = 0 b. symmetric c. based on degrees of freedom
d. all of these are correct

Michael is 36 years old

Step-by-step explanation:

Let M represent Michael's age, and let B represent Brandon's age,

"Michael is 4 times as old as Brandon" becomes

   M = 4B

"Michael is also 27 years older than Brandon" becomes

    M = B + 27

Since the two equations are equal to M, they are equal to each other, so we have...

4B = B  + 27            now solve for B...

3B = 27

B = 9

There fore

M = 9 + 27 = 36