填空题 设(X1，X2，…，X1)和(Y1，Y2，…，Y14)为分别来自正态总体N(p，，1)和N(pz，1)的两个独立样本，S12和S22分别是这两个样本的样本方差，令 Y=7S12+13S22，求概率P{Y＞23．83)（）．

单项选择题 根据短文回答 36～40 题。 Saving Money Where you save your money often depends on what you are saving for If you are saving to buy a dictionary or to go to a concert, then probably keep your money somewhere in your room.If you are saving for a big purchase like a mountain bike or a school trip, where would you save your money? ~One place to save money is the bank Putting your money in a savings account will help your money earn more money If you put your money in a piggy bank (猪形储蓄罐), one year later you'll still have the same amount of money you put in If you put your money in a savings account, one year later, you'll have more money than you put inWhy?When you keep your money in a bank, your money earns interest. Interest is the amount of money a bank pays you to use your money y The bank uses your money (and the money of other people, too) to loan money to people and businesses.The bank will send you a statement several times a year A bank statement tells you how much money there is in your account It also tells you how much interest you have earned If you leave your money in the bank, you can watch it grow!Another way you can save money is to buy a certificate of deposit or CD If you have some money that you don't need to use for a long time, this is a good way to make your money growYou can buy a CD at a bank You agree not to use the money for a certain period of time That period might be from six months to five years You can't touch your money during that time If you do, you must pay a penalty, or feeSince the bank is using your money for that time period, it will pay you interest you will earn more interest with a CD than in a savings account Can you guess why? It's because you promise to leave your money in the bank for a certain period of time, Banks pay different rates of interest so, and you may want to compare rates in newspaper ads before buying a CD． 第 36 题 Which way will help your money earn more money?（ ）A．Putting your money in your roomB．Putting your money in a piggy bankC．Putting your money in your pocketD．Putting your money in a savings account

填空题 设(X1，X2，…，X10)为来自正态总体N(μ，σ2)的样本，已知σ2=1．580 5，S2为样本方差，求概率P{S2＞2)（）．