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ACT หัวข้อ 17 6:02 การบรรยายภาษาอังกฤษ · คำบรรยายภาษาอังกฤษ + 中文 ลอยตัวบนภาพ
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A margin of error is added and subtracted in percentage points. Estimate 63% with margin 4 points gives 59%–67%. It is an interval from a procedure, not a guarantee that each person's response is near 63%.
有职务的排列区分顺序，无职务的组合去掉重复计数。
Random sampling supports population inference; random assignment addresses treatment comparisons.
期望净收益须扣成本，不代表每次结果。 不放回抽取要更新人数。
Each task gives its own data. Do not copy the worked example’s numbers.
每题给出独立数据，不能直接照搬例题数字。
Pause here and attempt the task before revealing the reasoning.
请先暂停独立作答，再查看推理。
Use the full context on the preceding pages.
结合前面各页的完整材料。
Ordered roles give 6 times 5, which is 30.
有顺序的职位安排共有六乘五，即三十种。
Unranked pairs count each pair twice in that product, so there are 6 times 5 over 2, which is 15.
不分顺序的两人组合在这个乘积中每对都被数了两次，所以共有六乘五除以二，即十五种。
Swapping people changes roles, but not an unranked committee.
交换两个人会改变职位，但不会改变一个不分职位的委员会。
Pause here and attempt the task before revealing the reasoning.
请先暂停独立作答，再查看推理。
Use the full context on the preceding pages.
结合前面各页的完整材料。
The remaining probability is 0.5.
剩下的概率是零点五。
The expected payout is 12 times 0.1, plus 3 times 0.4, plus 0 times 0.5, which is 2.4 tokens.
期望奖励等于十二乘零点一，加三乘零点四，加零乘零点五，即二点四个代币。
The expected net gain is the expected payout minus 2, which is 0.4 tokens per play.
期望净收益是期望奖励减二，即每局零点四个代币。
The actual net outcomes are 10, 1 and negative 2; none equals 0.4, which is a long-run mean under the model.
实际的净结果是十、一和负二，没有一个等于零点四；零点四是这个模型下的长期平均值。
Pause here and attempt the task before revealing the reasoning.
请先暂停独立作答，再查看推理。
Use the full context on the preceding pages.
结合前面各页的完整材料。
The probability of two reds is three fifths times two quarters, which is three tenths.
两次都是红球的概率是五分之三乘四分之二，即十分之三。
Exactly one red can occur as red then blue, or blue then red, so its probability is three fifths times two quarters, plus two fifths times three quarters, which is three fifths.
恰好一个红球可以是先红后蓝，也可以是先蓝后红，所以概率是五分之三乘四分之二，加五分之二乘四分之三，等于五分之三。
The second denominator is 4; the draws are dependent.
第二次的分母是四；两次抽取不是独立的。
Pause here and attempt the task before revealing the reasoning.
请先暂停独立作答，再查看推理。
Use the full context on the preceding pages.
结合前面各页的完整材料。
The interval runs from 62 percent minus 4, which is 58 percent, to 62 percent plus 4, which is 66 percent, where the subtraction is in percentage points.
区间从百分之六十二减四，即百分之五十八，到百分之六十二加四，即百分之六十六，这里加减的是百分点。
The population is registered members in the sampling frame.
总体是抽样框中的注册会员。
Nonmembers were not sampled, so the estimate does not establish all residents' support.
非会员没有被抽到，所以这个估计不能说明全体居民的支持程度。
Pause here and attempt the task before revealing the reasoning.
请先暂停独立作答，再查看推理。
Use the full context on the preceding pages.
结合前面各页的完整材料。
Random assignment supports a causal comparison of the instruction versions for these participants under the tested conditions, subject to variation.
随机分配支持对这些参与者、在所测试条件下的两种说明版本进行因果比较，但存在随机变异。
Volunteer selection limits population generalisation.
参与者是自愿报名的，这限制了推广到总体。
It does not establish that every future user will finish faster.
它并不能证明今后每位用户都会更快完成。
Pause here and attempt the task before revealing the reasoning.
请先暂停独立作答，再查看推理。
Use the full context on the preceding pages.
结合前面各页的完整材料。
People choosing to respond can differ systematically from those who do not.
选择回应的人可能与不回应的人存在系统性差异。
A margin for sampling variability does not remove that bias.
用来表示抽样变异的误差范围并不能消除这种偏差。
Select randomly from the defined target population and follow up nonresponse; still report limitations.
应当从界定好的目标总体中随机抽样，并跟进未回应者；即便如此，仍要报告局限。
Return to the task and explain why the method fits.
回到题目解释方法为何适用。
Original practice does not predict an official score. Complete required live or recorded evidence separately.
原创练习不预测官方分数；现场或录音证据需另行完成。
Pause and test yourself. Cover the worked answer, rebuild the answer to the last example in your own words, and name one condition that would change it before you check.
暂停一下，自我检测：遮住示范答案，用自己的话重做最后一个例子的答案，并在核对之前说出一个会改变结论的条件。