13.7 How to Use Microsoft Excel® for Regression Analysis

A computer program for multiple regression has been used to fit $\left(\overset{^}{y}\right)_{j} = b_{0} + b_{1} \cdot X_{1 j} + b_{2} \cdot X_{2 j} + b_{3} \cdot X_{3 j}$.

Part of the computer output includes:

1. Calculation of confidence interval for $b_{2}$ consists of _______± (a student's t value) (_______)
2. The confidence level for this interval is reflected in the value used for _______.
3. The degrees of freedom available for estimating the variance are directly concerned with the value used for _______

An investigator has used a multiple regression program on 20 data points to obtain a regression equation with 3 variables. Part of the computer output is:

1. 0.80 is an estimate of ___________.
2. 0.10 is an estimate of ___________.
3. Assuming the responses satisfy the normality assumption, we can be 95% confident that the value of $\beta_{2}$ is in the interval,_______ ± [t_.025 ⋅ _______], where t_.025 is the c…