【简答题】样本98, 100 , 98 , 100 , 101 , 103 的样本平均数为( ),的样本方差为( )
【单选题】We can draw the conclusion that ______.
A.
3G signals and current signals transfer data at the same speed
B.
3G mobile phone service will not be allowed for its bad impact
C.
more tests would be done to check the results of the study
D.
second-generation mobile phones will take the place of 3G mobile phone
【简答题】Signals received from satellite can help gather data.
【单选题】Signals can be ________.
C.
either digital or analog
D.
neither digital nor analog
【简答题】样本98,100,98,100,101,103的样本平均数为( ),样本方差为( )。
【简答题】已知一个样本:98,99,100,101,102.那么这个样本的方差是______.
【单选题】Computers can only recognize( )signals.