2. 职称英语
  3. [img]2014m9x/ct_egreqm_egreqbj_0056_20148[/img] [br] CIn this question, you are

[img]2014m9x/ct_egreqm_egreqbj_0056_20148[/img] [br] CIn this question, you are

游客2024-01-12  8
问题 [br]
选项
答案 C
解析 In this question, you are given that the number of defective parts in each of 50 boxes was recorded and that the average of the 50 recorded numbers was 1.12. You are also given that an error was made in recording one of the 50 numbers— the number 10 was recorded instead of the number 1—so the actual number of defective parts in this box is 9 less than the recorded number. Then you are asked to compare the actual average number of defective parts per box with 0.94.
   To determine the actual average number of defective parts per box, first note that the sum of the 50 recorded numbers equals the average of the 50 recorded numbers times 50—that is,(1.12)(50), or 56.
   Now you know that for 49 of the 50 boxes, the actual number of defective parts is equal to the recorded number; and for one box, the actual number is 9 less than the recorded number. From this you can conclude that the sum of the 50 actual numbers is equal to the sum of the 50 recorded numbers minus 9. So the sum of the actual numbers of defective parts is 56 - 9, or 47.
   Therefore, the actual average number ol defective parts per box is 47/50, or 0.94. Quantity A is equal to Quantity B, and the correct answer is Choice C.
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