There are 4 people of different heights standing in order of increasing height. The difference is 2 inches between the first person and the second person, and also between the second person and the third person. The difference between the third person and the fourth person is 6 inches and the average height is 77. How tall is the fourth person?
Choose the correct choice from the following choices:
A) 79
B) 81
C) 83
D) 85
E) 87
Let x be the height of the first person.   Then the heights are x, x+2, x+4, and x+10.   4x+16 = 4(77) = 308   x = 73 and the fourth person has a height of 73+10= 
<gadget id="calculator">73+10</gadget>
<output>83</output>
83 inches   The answer is 83.
<result>C</result>
There are 4 people of different heights standing in order of increasing height. The difference is 2 inches between the first person and the second person, and also between the second person and the third person. The difference between the third person and the fourth person is 6 inches and the average height is 77. How tall is the fourth person?