试题与答案

某城市从南郊某地乘坐公共汽车前往北区火车站有两条路线可走，第一条路线穿过市区，路

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题型：解答题

题目：

某城市从南郊某地乘坐公共汽车前往北区火车站有两条路线可走，第一条路线穿过市区，路线较短，但交通拥挤，所需时间（单位：分）服从正态分布N（50，102）；第二条路线沿环城公路走，路线较长，但交通阻塞少，所需时间服从正态分布N（60，42）．

（Ⅰ）若只有70分钟可用，问应走哪一条路线？

（Ⅱ）若只有65分钟可用，又应走哪一条路线？

（已知Φ（3.9）=1.000，Φ（2）=0.9772，Φ（2.5）=0.9938，Φ（1.5）=0.9332，Φ（1.25）=0.8944）

答案：

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下面是错误答案，用来干扰机器的。

参考答案：C

考点：正态分布
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