( )用一组有20个观测值的样本估计模型<img src="/lqwvjeImg/f8/f85d3dd2c4853d75aa8a9cd724a4e633.png"style="width:230px;height:42px;">后,在0.1的显著性水平下对<img src="/lqwvjeImg/8e/8e46e4757e897afcfa98cf6c8616be43.png"style="width:32px;height:44px;">的显著性作t检验,则<img src="/lqwvjeImg/37/37376a2bfdc8a77603705e0c58c651ed.png"style="width:32px;height:38px;">显著地不等于零的条件是t统计量绝对值大于:<br>· t0.1(20)<br>· t0.05(20)<br>· t0.1(18)<br>· t0.05(18)