c. Find the mean and variance of X.

5. Let X be a random variable with distribution function   Plot the graph of F(x) and then evaluate E(x).

6. There are two classes of Probability and Statistics course. The problems of the final exam are identical for the two classes. Let μ₁ and μ₂ denote the population means of scores of class A and class B, respectively, and σ₁ and σ₂ denote the population variances of scores of class A and class B, respectively. A random sample of 13 students are taken from class A and 11 students are taken from class B. The sample average and standard deviation of scores of each class are class A: X̄ₐ = 84, Sₐ = 4 and class B: X̄բ = 77, Sբ = 6. Test whether the population means of scores of the two classes are equal. Make assumptions if necessary.

a. What is the probability function of Y?

b. What is the cumulative distribution function of Y?

a. What is the fitted linear regression model?

b. What is the coefficient of determination of this model?

c. Does the model coefficients consistent with the prior knowledge that all three independent variables (x) have positive effect on the dependent variable (y)? Why or why not? Explain your answer.

1. 計算機的五大組成單元是：輸入、輸出、______、記憶和控制。

2. 網域名稱系統(Domain Name System, DNS)的任務是將網域名稱轉換成______。

3. ___________電腦系統主記憶體管理的一種技術。它使得應用程式認為它擁有連續可用的 主記憶體(一個連續完整的位址空間)，而實際上實體記憶體通常被分隔成多個主記憶體 碎片，還有部分暫時儲存在外部磁碟記憶體上，在需要時進行資料交換。這樣的技術使 處理大量資料的程式編寫變得更容易，也使實體記憶體的使用更有彈性。