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面经
Posted by Derek Jing
on
4:17 PM
in
Interview
发信人: sosohui (confused), 信区: Quant
标 题: 问个简单的问题
发信站: BBS 未名空间站 (Fri Jun 11 17:43:40 2010, 美东)
you have a digital clock ( no seconds ) that you randomly look
at once at a time defined as t1 and then keep looking until
it turns to the next minute defined as t2.
a) what is the expected value of t2-t1 ( i.e : mu ) and variance of
t2-t1 ( i.e :sigma squared )
b) what is mu plus or minus 2*sigma and what does it mean ?
理解为t1和t2是两个独立的U[0,60]吗？还是别的？b是说confidence interval吗？谢
谢。
标 题: 问个简单的问题
发信站: BBS 未名空间站 (Fri Jun 11 17:43:40 2010, 美东)
you have a digital clock ( no seconds ) that you randomly look
at once at a time defined as t1 and then keep looking until
it turns to the next minute defined as t2.
a) what is the expected value of t2-t1 ( i.e : mu ) and variance of
t2-t1 ( i.e :sigma squared )
b) what is mu plus or minus 2*sigma and what does it mean ?
理解为t1和t2是两个独立的U[0,60]吗？还是别的？b是说confidence interval吗？谢
谢。
