Therefore, the products of a, b, c and d are110×100 =10,10× 200 = 20,10.
That is to say, 10 product a, 20 product b, 5 product c and 15 product d should be selected from the sample ... (3 points)
(2) There are C250 = 1225 ways to choose 2 pieces from 50 pieces of products.
The method number of two identical products is C 210+C220+C25+C 215 = 350.
So the probability that the two products happen to be different models is 1? 350 1225 = 57 ...(6 points)
(iii) If the possible value of x is 0, 1, 2,3, then p (x = 0) = C35c315 =10455, and p (x =1) = c1.
C 210c15c315 = 225455, P(X=3)=C3 10C. What's your comment on this answer? Put away comments//high quality or satisfaction or special types or recommended answers dottimewindow.iperformance & window.iperformance.mark ('c _ best',+newdate); Lawyer recommendation service: If your problem has not been solved, please describe your problem in detail and seek free professional advice through Baidu Law Professional Edition. Other similar problems 202 1-09-06 A factory produced a product 16800 pieces from three production lines A, B and C. In order to check the quality of these products, it was decided to adopt stratification (May, 2023-072). In order to know the quality of parts, a factory had two production lines A and B. 1 12020-05-29 A factory produces two different models, A and B, and the product quantity ratio is 4:3. At present, 20 16-07-07(20 13? In order to know the product quality of two factories, 10 pieces were randomly selected from the products produced by two factories, and some 220 16-09-25 pieces were measured. In order to know the product quality of two factories, stratified sampling method was used to extract 14 and 5 pieces from the products produced by two factories. Measuring product 22011-12-13 A factory urgently needs 200 sets of parts of a certain model. When Xiaohong went to the manufacturer of this model to buy it, she learned from the manual that the product qualification rate was 96%, and 720 16-03-25 was to understand the product quality of the two factories. & 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 = 1720 137945；