This is the formula given for solving the Rate Of Return Earned From Securities: Sum of Interest Income From Securities Total Securities

How do I solve and wouldn't the Sum also be the Total?

Balance Sheet
	2018		2017
ASSETS
Loans	$ 14,050,453		$ 13,865,815
Securities	$ 4,215,761		$ 3,641,093
Overnight Loans	$ 558,454		$ 951,252
TOTAL INTEREST EARNING ASSETS	$ 18,824,668		$ 18,458,160
Cash	$ 486,812		$ 535,687
Capital Equipment	$ 846,989		$ 844,843
Other	$ 1,218,470		$ 1,192,051
TOTAL NON-INTEREST EARNING ASSETS	$ 2,552,271		$ 2,572,581
TOTAL ASSETS	$ 21,376,939		$ 21,030,741

Securities

Within 1 Year	Average Balance		Average Balance
U.S. Treasury	$ 811,835		$ 1,236,336
Government Agency	$ 2,176,143		$ 1,369,569
Residential Mortgage Backed Sec.	$ 373		$ 3
State, County & Municipal Bonds	$ 244		$ 757
Equity Securities	$ 15,313		$ 17,231
Corporate	$ 252,820		$ 163,170
TOTAL SHORT TERM SECURITIES	$ 3,256,728		$ 2,787,066
Longer than 1 year	Average Balance		Average Balance
U.S. Treasury	$ 75,984		$ 502,954
Agency	$ 416,066		$ 50,417
Residential MBS	$ 306,848		$ 143,542
State, County	$ 797		$ 499
Corporate	$ 159,338		$ 156,615
TOTAL LONG TERM SECURITIES	$ 959,033		$ 854,027
TOTAL SECURITIES	$ 4,215,761		$ 3,641,093