随机抽取某城市30天的空气质量状况统计如下: 污染指数(W)4560708

随机抽取某城市30天的空气质量状况统计如下:

污染指数(W

45

60

70

80

95

110

125

天数(d

2

4

3

9

6

4

2

其中,W50时,空气质量为优;50W100时,空气质量为良;100W150时,空气质量为轻微污染,请你用所学知识估计该城市一年(365天计)中,有多少天空气质量达到良以上(包括良).

答案

根据题意:随机抽取的30天中,空气质量达到良以上的天数为:2+4+3+9+624(天),随机抽取的30天中,空气质量达到良以上的频率为0.8,估计全年365天中空气质量达到良以上的天数为365×0.8292(天).

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