An article reports measurements of expansion for several concrete bridges in the area of Quebec City. Following are measurements of horizontal and vertical expansion (in parts per hundred thousand) for several locations on the Pere-Lelievre Bridge.
Horizontal 20 15 43 5 18 24 32 10 21
Vertical 58 58 55 80 58 68 57 69 63
a) Compute the least-squares line for predicting vertical expansion from horizontal expansion.
b)Compute 95% confidence intercals for B0 and B1.
c) Compute a 95% prediction interval for the vertical expansion at a location where the horizontal expansion is 25.
d) It is desired to predict the vertical expansion in two locations. In one location the horizontal expansion is 15, and in the other it is 30. If 95% prediction intervals are computed for the vertical expansion in both locations, which one will be wider? Explain?