Answer:
7%
Step-by-step explanation:
The computation of the annual interest rate is shown below:
Given that
 N = 20 × 12 = 240 
 Present Value(PV) = $0 
 Periodic Payments (PMT ) = $150 
 Future Value (FV) = $78,595 
 Type = 1 as this is an annuity due. 
 Now Use the Rate function in excel, 
 =RATE (Nper, Pmt,-Pv, FV,Type) 
 = RATE(240,-150,0,78595,1,0) 
 = 0.0058 
 Now
Yearly Rate is 
= 0.0058 × 12 
 = 7%