The biggest difference between the phone interview and the in-person interviewer lies on whether the interviewer and the interviewee have the face to face contact.
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It doesn’t matter whether the interviewee smiles or not during the phone interview, since the interviewer cannot see him/her.
A. 对
B. 错
有关方差的说法正确的是()
A. D(C)=C(C为常数)
B. D(CX)=D(X)
C. D(C+X)=D(X)(C为常数)
D. 方差就是期望。
已知离散型随机变量X服从二项分布,且期望E(x)=2.4,方差D(X)=2.16,则其参数n,p的值为()
A. n=4,p=0.6
B. n=6,p=0.4
C. n=8,p=0.3
D. n=24,p=0.1
期望刻画了随机变量的平均水平,方差刻画了随机变量的离散程度。
A. 对
B. 错