There are 7 students in the 2nd group of class 5, 1 minute, and the average score of the first 4 students is 95, the average score of the last 4 students is 80, and the average score of the 7 students is 85. How many jumps did the fourth person jump? ．
五1班第2小组有7位同学进行1分钟跳绳测试，前4人平均成绩是95个，后4人平均成绩是80个，7个人的平均成绩是85个，第四人跳了多少个．
<gadget id="calculator">95 * 4</gadget>
<output>380</output>

<gadget id="calculator">80 * 4</gadget>
<output>320</output>

<gadget id="calculator">380 + 320</gadget>
<output>700</output>

<gadget id="calculator">85 * 7</gadget>
<output>595</output>

<gadget id="calculator">700 - 595</gadget>
<output>105</output>

<result>105</result>