第一个问题那两列一样是因为自由度为1，sum/1=Mean
第二个问题多元回归除对回归方程要做显著性检验外还需要需要对回归系数做显著性检验，这就是会有F的原因，当然这里也可以用t检验，但是可以用t检验那就一定可以用F检验，这个从统计量就能看出来
回答完毕，希望对lz有用

In response to question 2, You should know that you are fitting a ordinary linear model with 4 predictors (not the traditional one way ANOVA for single factor problem), that is why you got 4 F values. Also take care when you are trying to interpret them, since the variables are not mutually orthogonal. (check the concepts such as "sequential sum squares" and "partial sum squares")
To sum, before applying any software to data, try to understand what model you used and how to interpret it.

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