硕士招生考试中的概统
- 本楼收录近 5 年考研数学(一)中的概率论与数理统计题目。
2018 年
2019 年
2020 年
2021 年
2022 年
第 4 章:参数估计
习题
3. 书后答案足够。
4. 书后答案很漂亮。
补充习题
2022.10.24
2022.10.26
myrepeat = 20000;
xx = rnorm(myrepeat, 0, 1);
yy = rnorm(myrepeat, 1, 2);
zz = xx - yy;
mynumber = sum(zz > 0);
myfraction = mynumber / myrepeat
myfraction
(最近没空学 R
,弄清楚了以后再细说。)
2022.11.09
# R code
mysamplesize = 15;
alpha = 0.05;
mytheta = 1;
mysample = rexp(mysamplesize, rate = 1) + mytheta;
mymle = sort(mysample)[1];
bootstrapsize = 1000;
bootstrapestimates = rep(0, bootstrapsize);
for(ii in 1: bootstrapsize){
bootstrapsample = rexp(mysamplesize, rate = 1) + mymle;
bootstrapestimates[ii] = sort(bootstrapsample)[1];
}
bootstrapquantiles = sort(bootstrapestimates - mymle)
lowerquantile = bootstrapquantiles[round(bootstrapsize * alpha * 0.5)]
upperquantile = bootstrapquantiles[round(bootstrapsize * (1 - alpha * 0.5))]
lowerbound = mymle - upperquantile
upperbound = mymle - lowerquantile
print(lowerbound)
print(upperbound)