Question

Kathleen correctly determines four arithmetic means between −7 and 14. What values does Kathleen determine?

Kathleen determines the four arithmetic means to be −2.8 , 1.6, 5.8, and 10.
Kathleen determines the four arithmetic means to be −2.8 , 1.4, 5.6, and 9.4.
Kathleen determines the four arithmetic means to be −2.8 , 1.4, 5.6, and 9.8.
Kathleen determines the four arithmetic means to be −2.8 , 1.6, 5.6, and 9.8.

Answer 1

Kathleen determines the four arithmetic means to be −2.8 , 1.4, 5.6, and 9.8.

Explanation:

The overall interval is 14 -(-7) = 21 units in length. The four equally-spaced "means" divide the interval into 5 equal parts, each one of which is ...

21/5 = 4.2

The four means are ...

-7 +4.2 = -2.8

-2.8 +4.2 = 1.4

1.4 +4.2 = 5.6

5.6 +4.2 = 9.8