Savannah took out a 7/1 variable-rate mortgage for $114,000. The interest rate for the first period was fixed at 6.15%, and the loan was amortized over 30 years. At the end of the initial loan period, the interest rate was 7.15%, plus a 1.25% margin. 

Part I: What was Savannah\'s monthly payment for the first 7 years of the loan? 

Part II: What was the remaining balance on Savannah\'s loan after the initial fixed-rate period? 

Part III: What was the interest rate in the eighth year of Savannah\'s mortgage? 

Part IV: What was Savannah\'s monthly payment in the eighth year of her mortgage?