问题
单项选择题
对某样本的相关系数r和0的差别进行检验，结果tr＜t0.05(n-2)，因此
A．两变量的差别有统计意义
B．两变量存在相关关系
C．两变量肯定不存在相关关系
D．两变量存在直线相关的可能性小于5%
E．根据本资料尚不能认为两变量间存在直线相关关系
答案
参考答案：E
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对某样本的相关系数r和0的差别进行检验，结果tr＜t0.05(n-2)，因此
A．两变量的差别有统计意义
B．两变量存在相关关系
C．两变量肯定不存在相关关系
D．两变量存在直线相关的可能性小于5%
E．根据本资料尚不能认为两变量间存在直线相关关系
参考答案：E
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| Knowing how much her own children loved presents at Christmas, Ann Sutton, a social worker, always tried to seek help for one or two poor families. This year, Kinzie, Ann's seven-year-old daughter, was 1 that Santa Claus would make a special visit to a young mother named Ashley who worked in a factory and was 2 her 12-month-old son, Evan, and her 12-year-old brother, Kenny, by herself. At a 3 dinner, the phone rang. A representative from a local charity was calling to say that the 4 Ann had requested for Ashley had been cancelled. No Santa Claus, no presents, nothing. Ann saw the cheer fade away from her children's faces at the news. Without a word, Kinzie 5 down from her chair and ran from the room. Now, it didn't feel much 6 Christmas anymore. Kinzie returned, her face set with determination. She had opened up her piggy 7 , and now she counted out the coins and broken dollar 8 , one by one, onto the dining table: $3.30. Everything she had. "Mom," she told Ann, "I know it's not much. 9 maybe this will buy a present for the baby." Then 10 everyone was reaching into pockets and purses. Adding to Kinzie's gift became a game, with everyone 11 for loose change. By the time the search ended, there was a small mountain of bills and a neat pile of coins. The 12 : $130, plenty for a Christmas for three. "God multiplied your gift," Ann said to Kinzie. That evening, Kinzie went with her mother and sisters to 13 the money. On Christmas Eve, Ann 14 through the pouring rain to the small cottage where the family lived. When Ashley opened the door, Ann stood under her umbrella and 15 the astonished woman a merry Christmas. Then she began to 16 the gifts from the car, handing them to Ashley one by one. Ashley laughed in disbelief, and still the presents came. Ann abandoned the umbrella, and the young woman joined her in the rain, passing gifts 17 to Kenny. "Please, can I open up just one tonight?" he begged. Soon both women were 18 to the skin, and surprise had turned to something 19 , the kind of joy that brought them close to tears. Reflecting on a little girl's generosity, Ashley says she hopes she'll one day be able to do something similar for someone else in 20 . "Kinzie could have used that money for herself, but she gave it away," Ashley says. "She's the type of kid I'd like my son to grow up to be." | ||||
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