(1) The direct bonds and obligations of the United States, or in mutual fund shares of a registered investment company or common trust funds which are invested only in direct bonds and obligations of the United States, or obligations issued separately or collectively by or for federal land banks, federal intermediate credit banks and banks for cooperatives under the act of Congress known as the Farm Credit Act of 1971, 85 Stat. 583, 12 U.S.C § 2001 and amendments to that act, or Home Owners' Loan Corporation bonds, guaranteed in principal and interest by the United States government, procuring them always at the best possible salable or market price obtainable in the interest of the ward; bonds and/or debentures issued by any Federal Home Loan Bank organized under the Federal Home Loan Bank Act of the United States;

(2) The bonds of the state of Tennessee, procuring the bonds always at the best possible salable or market price obtainable in the interest of the ward;

(3) The bonds of any county in this state having a population of fifteen thousand (15,000) by the last federal census next preceding the date of the investment, that has not defaulted within twenty (20) years preceding the investment for more than thirty (30) days in the payment of any part either of principal or interest of any bond, note or other evidence of indebtedness, procuring the bonds always at the best possible salable or market price obtainable in the interest of the ward; provided, that before investment is made in the county bonds as authorized in this subdivision (3), there has been filed with the clerk of the court having jurisdiction of the guardianship a certificate by the chief financing officer, or treasurer of the county, certifying to the prerequisites as provided in this subdivision (3) regarding population and status of the bonds;

(4) The bonds or notes of any city or town in this state that has a population as shown by the last federal census next preceding the investment of not less than forty-five thousand (45,000) and has not defaulted within twenty (20) years preceding the investment for more than thirty (30) days in the payment of any part either of principal or interest of any bond, note or other evidence of indebtedness, procuring the bonds or notes always at the best possible salable or market price obtainable in the interest of the ward; provided, that before investment is made in city bonds as authorized in this subdivision (4), there has been filed with the clerk of the court having jurisdiction of the guardianship a certificate by the chief financing officer or treasurer of the city certifying to the prerequisites as provided in this subdivision (4) regarding population and status of the bonds;

(5) First mortgage or trust deed on real estate situated in the county of the guardianship, the amount lent not to exceed one half (½) of the actual cash value of the real estate mortgaged; provided, that the real estate has been appraised and reported as to its cash market value by three (3) disinterested persons appointed for that purpose by the chancery or probate court of the county in which the land lies, upon application to the court to that end, and approved by the court;

(6) Certificates of deposit, time deposits, savings deposits, and any other accounts, issued and accepted by any state or national bank that has insured its accounts with the federal deposit insurance corporation, up to the maximum amount insured by the federal deposit insurance corporation; and

(7) Any type of savings account or deposits (including certificates of deposit) in an amount that is insured with an insurer approved by the commissioner of commerce and insurance.