PSY 310: Statistical Inference

LC is the final grade which is 1/3 scaled midterm and 2/3 the scaled final.

$$\begin{array}{ccc}l& =& \frac{m_s}{3}+\frac{2m_s}{3}\\ m_s& =& \frac{m-\stackrel{\_}{m}}{{\sigma }_m}\\ f_s& =& \frac{f-\stackrel{\_}{f}}{{\sigma }_f}\\ {\sigma }_l^2& =& l_{\frac{m_s}{3}+\frac{2f_s}{3}}\\ & =& varh\left(\frac{m_s}{3}+\frac{2f_s}{3}\right)\\ & =& \frac{{\sigma }_{m_s}}{3}+\frac{2{\sigma }_{m_s}}{3}\end{array}$$

That is in the output file.

I would do this using:

$$\begin{array}{ccc}{\rho }_{x,y}& =& \frac{{\sigma }_{x,y}}{{\sigma }_x{\sigma }_y}\\ {\sigma }_{x,y}& =& {\rho }_{x,y}{\sigma }_x{\sigma }_y\end{array}$$

Since the correlation and the deviations are in my output. I was mistaken however about having SPSS in my lab and I can't currently see the numbers in my output. Could I get partial credit for knowing what I needed to do?

I would think this is simply that the computed value of the covariance from the equation from part (a) agrees with the computed variance from part (c). I can't really do this since I can't see the output.