NO.PZ202306130100003301
问题如下：
Based on Exhibit 1 and Exhibit 2, if Liu were to graph the 50 observations, the
scatter plot summarizing this relation would be best described as:
选项：
A.
horizontal.
B.
upward sloping.
C.
downward sloping.
解释：
C is correct. The slope coefficient (shown in Exhibit 2) is negative.
Exhibit1 中-9.2430除以X的variance是负数，是否也可以证明斜率是负数？
