From the base price level of $100$ in $1981,$ Saudi Arabian and U$.$S$.$ price levels in $2010$ stood at $210$ and $100,$ respectively. Assume the $1981$ $$/$riyal exchange rate was $$0\mathrm{.}30/$riyal$.$ Suggestion: Using the purchasing power parity, adjust the exchange rate to compensate for inflation. That is$,$ determine the relative rate of inflation between the United States and Saudi Arabia and multiply this times $$/$riyal of $0\mathrm{.}30.$ What should the exchange rate be in $2010?$