What is the value of x and y in the geometrical progression 5,x,y,-5/8.
a = 5
ar = x
ar^2 = y
ar^3 = -5/8
5r^3 = -5/8
r^3 = -1/8
r = -1/2
then x = ar = 5(-/2) = -5/2
and y = ar^2 = 5(-1/2)^2 = 5/4
ar = x
ar^2 = y
ar^3 = -5/8
5r^3 = -5/8
r^3 = -1/8
r = -1/2
then x = ar = 5(-/2) = -5/2
and y = ar^2 = 5(-1/2)^2 = 5/4