Past exam paper Qs picture by nuclearone - Photobucket
Thanks, help greatly appreciated
Past exam paper Qs picture by nuclearone - Photobucket
Thanks, help greatly appreciated
(a) $\displaystyle \overline{X}$ ~ Normal $\displaystyle \left( \mu = 30, ~ \sigma = \frac{2.5}{\sqrt{100}} = 0.25\right)$.
Calculate $\displaystyle \Pr(29.5 < \overline{X} < 30.5)$.
(b) $\displaystyle 0.4 = z_{0.025} \frac{2.5}{\sqrt{n}}$. Solve for $\displaystyle n$.