題目列表(包括答案和解析)
在300個數(shù)據(jù)中,用隨機抽樣的方法抽取50個數(shù)據(jù),在頻率分布表中,52.5~55.5這一組的頻率是0.3,那么估計總體數(shù)據(jù)落在52.5~55.5之間的約有
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某年級300名同學(xué)的體重如下(單位:kg):
49, |
48, |
43, |
52, |
62, |
74, |
43, |
51, |
46, |
47, |
51, |
45, |
50, |
46, |
52, |
54, |
50, |
58, |
55, |
58, |
48, |
48, |
53, |
49, |
56, |
55, |
56, |
43, |
54, |
68, |
47, |
61, |
51, |
44, |
41, |
49, |
53, |
52, |
49, |
52, |
62, |
58, |
52, |
54, |
50, |
47, |
66, |
46, |
47, |
44, |
72, |
55, |
43, |
60, |
51, |
41, |
48, |
49, |
43, |
52, |
63, |
44, |
41, |
47, |
48, |
49, |
55, |
53, |
58, |
50, |
50, |
43, |
60, |
61, |
52, |
50, |
42, |
44, |
46, |
67, |
47, |
66, |
46, |
47, |
69, |
48, |
43, |
50, |
50, |
43, |
46, |
47, |
44, |
42, |
55, |
56, |
55, |
56, |
43, |
54, |
49, |
56, |
55, |
56, |
65, |
43, |
60, |
51, |
41, |
48, |
43, |
52, |
62, |
46, |
52, |
54, |
50, |
58, |
58, |
52, |
49, |
48, |
43, |
50, |
50, |
47, |
44, |
42, |
55, |
63, |
60, |
48, |
43, |
50, |
50, |
43, |
49, |
53, |
52, |
49, |
48, |
43, |
50, |
50, |
47, |
44, |
49, |
48, |
43, |
44, |
42, |
55, |
43, |
42, |
64, |
46, |
47, |
48, |
43, |
50, |
44, |
41, |
47, |
48, |
49, |
55, |
53, |
58, |
55, |
73, |
60, |
51, |
41, |
53, |
49, |
56, |
55, |
56, |
43, |
54, |
44, |
41, |
47, |
48, |
49, |
55, |
41, |
48, |
43, |
42, |
44, |
46, |
47, |
42, |
55, |
43, |
60, |
68, |
43, |
50, |
48, |
43, |
52, |
62, |
43, |
51, |
46, |
47, |
51, |
45, |
49, |
46, |
72, |
54, |
50, |
58, |
47, |
61, |
51, |
44, |
41, |
44, |
41, |
49, |
73, |
52, |
49, |
52, |
49, |
56, |
55, |
56, |
43, |
54, |
48, |
47, |
61, |
50, |
50, |
43, |
46, |
47, |
44, |
42, |
48, |
43, |
52, |
62, |
55, |
41, |
48, |
43, |
42, |
44, |
46, |
47, |
43, |
46, |
67, |
44, |
42, |
44, |
41, |
47, |
48, |
49, |
55, |
53, |
72, |
54, |
50, |
58, |
55, |
58, |
49, |
48, |
43, |
52, |
53, |
54, |
48, |
47, |
61, |
51, |
44, |
4l, |
49, |
53, |
72, |
49, |
52, |
47, |
66, |
46, |
47, |
49, |
48, |
43, |
50, |
49. |
(1)請用計算器或計算機計算總體的平均數(shù)、方差和標準差(精確到0.01),并繪制總體的頻數(shù)分布直方圖;
(2)請用簡單隨機抽樣方法,從上述調(diào)查的數(shù)據(jù)中分別抽取樣本容量為10的兩個樣本,并分別計算這兩個樣本的平均數(shù)、方差和標準差,分別繪制這兩個樣本的頻數(shù)分布直方圖,結(jié)果一致嗎?如果分別抽取樣本容量為20、50的兩個樣本呢?
(3)通過以上的抽樣和計算,你有什么發(fā)現(xiàn)?并與同伴交流.
分組 | 頻數(shù) | 頻率 |
3.95~4.25 | 2 | 0.04 |
4.25~4.55 | 6 | 0.12 |
4.55~4.85 | 25 | |
4.85~5.15 | ||
5.15~5.45 | 1 | 0.02 |
合計 | 1 |
分組 | 頻數(shù) | 頻率 |
3.95~4.25 | 2 | 0.04 |
4.25~4.55 | 6 | 0.12 |
4.55~4.85 | 25 | |
4.85~5.15 | ||
5.15~5.45 | 1 | 0.02 |
合計 | 1 |
分組 | 頻數(shù)累計 | 頻數(shù) | 頻率 |
59.5-64.5 | - | 1 | 0.033 |
64.5-69.5 | T | 2 | 0.067 |
69.5-74.5 | 2 | 0.067 | |
74.5-79.5 | 3 | ||
79.5-84.5 | - | 1 | 0.033 |
84.5-89.5 | 正 | 9 | 0.300 |
89.5-94.5 | 正- | 6 | 0.200 |
94.5-99.5 | 正 | 0.167 | |
99.5-104.5 | - | 1 | 0.033 |
合計 | 30 | 1.000 |
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