 <translate> When Joe added 20% more data points to the dataset, the data points in the dataset increased by 20 / 100 * 200 = 40 data points. The total number of data points increased to 200 + 40 = 240. If he reduced the data points by 1 / 4 of the total data points, the data points reduced by 1 / 4 * 240 = 60. The total number of data points left in the dataset after Joe reduced the data points by 1 / 4 of the total data points is 240 - 60 = 180.
Thus, the answer is 180. <yor> Nígbà tí Joe fi 20% àwọn ìsọfúnni kún ìsọfúnni náà, àwọn ìsọfúnni náà fi 20 / 100 * 200 = 40 ìsọfúnni kún un. Apapọ iye awọn aaye data pọ si 200 + 40 = 240. Tó bá fi ìdajì ìsọfúnni tó wà nínú ìsọfúnni náà dín kù, ìdajì ìsọfúnni tó wà nínú ìsọfúnni náà á dín kù sí ìdajì ìsọfúnni tó wà nínú ìsọfúnni náà. Apapọ iye awọn aaye data ti o ku ninu data data lẹhin ti Joe dinku awọn aaye data nipasẹ 1 / 4 ti awọn aaye data lapapọ jẹ 240 - 60 = 180. Nítorí náà, ìdáhùn náà ni 180. 