(2) According to the principle of stratified sampling, the ratio of sampling numbers of three fractional segments is equal to the ratio of corresponding frequencies.
In addition, the frequency ratio of the scores of [70,30], [30,90] and [90,n00] is equal to 5: f: n, from which it can be concluded that there are 5 people with the score of [70,30] and F people with the score of [30,90] and [90,n00].
Anyone who takes a photo from it has different results, as shown in Figure 3 = 5.
Number of students with scores in [70,30] band X All values are 0, n, f and numbers.
Their probabilities are: Tu Tu 5 graph =n5 graph for p (x = 0), F graph = n55 graph for n5 for p (x = n),
N f5 and p (x = f) in Figure 5 = Figure 05 =n5f3. , figure 55 of p (x = figure) =n05 = 5f3.
∴X's distribution list is
? x？ 0 ? n？ f？ Figure? p？ N5 diagram? N55 diagram? n5f3？ 5f3: ex = 0× n5 diagram +n×n55 diagram +f×n5f3+ diagram× 5f3 = I praised it and stepped on it. What's your comment on this answer? Comments put away the recommended lawyer service: If your problem is not solved, please describe your problem in detail and provide free professional consultation through Baidu Legal Pro. Other similar questions 2023-04- 12 In a math exam, Xiaoming scored 72 points, more than half of the students in the class. The statistical data used to draw this conclusion are: (1) The stem leaf diagram (figure 1) and frequency distribution histogram (figure 2) of a mathematical test result in February 2016-2-065433 in a senior three experimental class of a middle school were damaged to varying degrees. The histogram of frequency distribution is as follows: (1) According to the frequency of 320 13-08-04, the average score of a class in mathematics examination is 78, and the stem leaf diagram and frequency distribution histogram of a class in senior three are damaged to varying degrees. According to this answer, the visible part of12016-12-065438+is as follows. According to this, the stem-leaf diagram and frequency distribution histogram of a math test score of a class in grade one of a school at 20 16- 12 were destroyed by different programs, but the diagram shows the visible part, so there are many similar problems. & gt recommended for you: F.context('cmsRight', [{'URL':'/d01373f082025aaf511aa256e9edab64034f1a07? x-BCE-process = image % 2f resize % 2Cm _ lfit % 2Cw _ 450% 2Ch _ 600% 2c limit _ 1% 2f quality % 2Cq _ 85% 2f format % 2Cf _ auto '，' contractId':'A24KA00562 '，}，{ ' URL ':/s？ word = % E6 % AC % A7 % E6 % B4 % B2 % E6 % 9D % AF & sa = searchpromo _ ozb _ zhidao _ tuijian '，' src ':'/3 BF 33 a 87 e 950352 AAF 5 df 4954 143 fbf2b 2 1 18 b6b？ x-BCE-process = image % 2f resize % 2Cm _ lfit % 2Cw _ 450% 2Ch _ 600% 2c limit _ 1% 2f quality % 2Cq _ 85% 2f format % 2Cf _ auto '，' contractId ':' '，}])； Is Huaqiang North's second-hand mobile phone reliable? Why is the cost of cancer treatment getting higher and higher? What impact will the "network toilet" have? The price of electric cars has dropped many times. Is the quality guaranteed? I recommend f.context ('recbrand', [{"img": "\/86D6277F9E2F07083523F69DFB 24B 899A901F20d? x-BCE-process = image % 2f resize % 2Cm _ lfit % 2Cw _ 450% 2Ch _ 600% 2c limit _ 1% 2f quality % 2Cq _ 85% 2f format % 2Cf _ auto "，" url":"/hm.js？ 6859 ce 5a af 00 FB 00387 e 6434 E4 FCC 925 "； var s = document . getelementsbytagname(" script ")[0]； s.parentNode.insertBefore(hm，s)； })(); window . TT = 1720048866；