ExxonMobil reports total assets of $188 billion and total liabilities of $87 billion. Citigroup reports total liabilities of $1,300 billion and stockholders' equity of $90 billion. Amazon reports total assets of $2.7 billion and total stockholders' equity of $0.10 billion. Nike reports an increase in assets of $1.00 billion and an increase in liabilities of $0.5 billion. Kellogg's reports a decrease in liabilities of $0.44 billion and an increase in stockholders' equity of $0.04 billion. (Enter your answers in billions rounded to 2 decimal places. Negative amounts should be indicated by a minus sign.) Required: What is the amount of stockholders' equity of ExxonMobil