2.已知一組數(shù)據(jù):125,121,123,125,127,129,125,128,130,129,126,124,125,127,126,122,124,125,126,128.
(1)填寫(xiě)下面的頻率分布表:
分組 |
頻數(shù) |
頻率 |
[121,123) |
|
|
[123,125) |
|
|
[125,127) |
|
|
[127,129) |
|
|
[129,131] |
|
|
合計(jì) |
|
|
(2)作出頻率分布直方圖;
(3)根據(jù)頻率分布直方圖求這組數(shù)據(jù)的眾數(shù)、中位數(shù)、平均數(shù)及第75%分位數(shù).