Past exam paper Qs picture by nuclearone - Photobucket

Thanks, help greatly appreciated

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- May 7th 2009, 02:04 AMarthus123Help on statistics past paper questions pls?
Past exam paper Qs picture by nuclearone - Photobucket

Thanks, help greatly appreciated - May 7th 2009, 04:32 AMmr fantastic
(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 $\displaystyle n$. - May 7th 2009, 04:56 AMarthus123
Thank you mr. fantastic! :O