Use the approximations $\ln 2 \approx 0.693$ and $\ln 3 \approx 1.099$ together with the properties stated in Theorem A to calculate approximations to each of the following. For example, $\ln 6=$ $\ln (2 \cdot 3)=\ln 2+\ln 3 \approx 0.693+1.099=1.792$.
(a) $\ln 6$
(b) $\ln 1.5$
(c) In 81
(d) $\ln \sqrt{2}$
(e) $\ln \left(\frac{1}{36}\right)$
(f) $\ln 48$