问题如下:
When can you use the normal distribution to approximate the Poisson distribution, assuming you have n independent trials, each with a probability of success of p?
选项: When
the mean of the Poisson distribution is very small
When the variance of the Poisson distribution is very small
C.When the number of observations is very large and the success rate is close to 1
D.When the number of observations is very large and the success rate is close to 0
解释:
The normal approximation to the Poisson improves when the success rate, χ, is very high. Because this is also the mean and variance, answers A and B. are wrong. In turn, the binomial density is well approximated by the Poisson density when np = χ is large.
P->0, 为什么不选D?