Russell starling, an australian citizen and resident, received the following investment income during 2018: $5,000 of dividend income from ownership of stock in a u. s. corporation, $10,000 interest from a certificate of deposit in a u. s. bank, $3,000 of interest income earned from a loan to clint westwood, a u. s. citizen, and $2,000 capital gain from sale of a stock in a u. s. corporation. how much of russell's income will be subject to u. s. taxation in 2018?