On Juan's 26th birthday, he deposited $7,500 in a retirement account. Each year thereafter he deposited $1,000 more than the previous year. Using a gradient series factor, determine how much was in...

Extracted text: On Juan's 26th birthday, he deposited $7,500 in a retirement account. Each year thereafter he deposited $1,000 more than the previous year. Using a gradient series factor, determine how much was in the account immediately after his 35th deposit if: a. The account earned annual compound interest of 5%. b. The account earned annual compound interest of 6%.