Answer:

A=103.04

Step-by-step explanation:

Suppose a varies jointly as b and c, and a = 145 when b = 9 and c = 5.

A=kbc

145=k(9)(5)

145=45k

3.22=k

Find a when b = 8 and c =4

A=kbc

A=(3.22)(8)(4)

A=103.04