纸上的疑问

老师你好，21题看不懂解释

老师，您好！在直接法计算CFO时，“四支”中支付给供应商的钱，严格一点来讲要不要考虑prepaid expenses，即-cash paid to suppliers=-COGS+ΔA/P+depreciation included in COGS-Δinventory-Δprepaid expenses？

根据short put和 long call的payoff图为什么能得出风险敞口为long?

这道题说 with a sample standard deviation of 12 hours， 可以算是方差未知吗？

听晕了 X拔到底定义的是什么哦， 抽样样本的平均值吗？比如100个X，n=50,就是说100个数里面抽取了50个数字。 然后这样的抽样过程一致反复，挑选了若干个50个数字的样本。 每个样本去计算一下平均值为X1 X2 X3 。。。。然后这些X1 X2 X3再去算平均值就是X拔吗？

This process is used to estimate the population mean and standard deviation, which usually are unknown. 这题答案里的这句话是不是有错？老师说符合中心极限定理的条件是 known mean and known standard deviation.

P-value中是不是不考虑单双尾检验，只需比较P-value和α的大小即可？

这题解体过程为什么不是12-5=7（nominal rate - inflation = real rate）,7-3=4 (real rate - risk free rate = risk premium)?

F(21) = 1.00 The probability density function for a continuous uniform distribution is calculated as follows: F(X) = (X – a) / (b – a), where a and b are the lower and upper endpoints, respectively. (If the given X is greater than the upper limit, the probability is 1.0.) , 如果below the lower endpoint ，概率是多少?