(i)[4]
A certain game reserve contains $430$ adult female giraffes. Determine how many of these adult female giraffes are expected to have a weight below $700\text{ kg}$.
(ii)[3]
If $90\%$ of adult female giraffes have weights between $(830 - w)\text{ kg}$ and $(830 + w)\text{ kg}$, determine the value of $w$.
(iii)[3]
Adult male giraffe weights are normally distributed with mean $1190\text{ kg}$ and standard deviation $\sigma\text{ kg}$. If $83.4\%$ of adult male giraffes weigh above $950\text{ kg}$, determine $\sigma$.