问题 问答题 计算题

为研究产品销售额与销售利润之间的关系,某公司对所属6家企业进行了调查,设产品销售额为x(万元),销售利润为y(万元)。调查资料经初步整理和计算,结果如下:∑x=225∑x2=9823∑y=13∑y2=36.7∑xy=593要求:(1)计算销售额与销售利润之间的相关系数;(2)配合销售利润对销售额的直线回归方程。(3)解释回归系数的含义

答案

参考答案:

rr

nxyxy

nx2(x)2ny2(y)2

659322513

2

2

完形填空

第二节完形填空(共20题,满分20分)

About three years 30 , something terrible 31 to me. 32 six hours of terror have broken my body and 33. You think I am a very 34 man—but I am not. It 35 less than a single day to change my 36 from black to white. One day, my 37 brothers and I were 38 back from the islands, our boat 39 of fish. 40 , the sky was 41 with dark clouds and in 42 a minute we were in a terrible storm. An 43  wave covered our boat and my younger brother 44 into the sea. Our boat survived, and I was trying to recover 45 my elder brother put his mouth 46 to my ear, and 47 out the 48 word “Whirlpool!” With the wind and waves we were going in the direction of the whirlpool, and 49 could save us!

30. A. before         B. after          C. ago              D. late

31. A. took place      B. happened      C. changed         D. informed

32. A. that           B. those          C. this              D. these

33. A. soul           B. heart          C. head             D. mind

34. A. rich           B. poor          C. young            D. old

35. A. spent          B took           C. paid              D. cost

36. A. hair           B. face           C. mouth            D. feet

37. A. three          B. one            C. two              D. four

38. A. came          B. going         C. moving           D. coming

39. A. felt           B. full            C. filled            D. fall

40. A. All at once     B. Instead         C. Meanwhile       D. Besides

41. A. covered       B. discovered       C. recovered        D. covering

42. A. no less than    B. less than        C. more than        D. no more

43. A. enormous      B. small           C. mini            D. enough

44. A. fall into        B. felt into         C. fell into         D. fallen into

45. A. while          B. when          C. as             D.  before

46. A. tightly         B. closely          C tight            D. close

47. A. screamed       B. said            C .told            D. whispered

48. A. terrified        B. terrifying        C. satisfied        D. satisfying

49. A. nothing        B. everything        C. something      D. anything

单项选择题