Kelvin is at his house located at (3, 4) on a coordinate plane and walks to the store located at (1, 0). The store is located exactly half way between Kelvin’s house and Mitch’s house. To the nearest tenth, what is the distance between Kelvin’s house and Mitch’s house?

The location of Kevin's house is (3,4) and that of store is (1,0). The distance between them is give by:
d=√(x-x_1)^2+(y-y_1)^2
plugging our values we obtain:
d=√[(3-1)^2+(4-0)^2]
d=√[2²+4²]
d=√(4+16)
d=√20
d=2√5
since the distance from Kevin's house to the store is the same as the distance from Mitch's house to the shop, then the distance between Kevin's and Mitch's house is :
2×2√5
=4√5 units