Answer:
172 cm
Explanation:
The total height of the first 7 people is the average of the 7 people multiplied by the number of people, which is 156 * 7 or 1092. Using the same method, the total height of the first 8 people is 158*8 or 1264. The eighth person must be 1264 - 1092 cm tall or 172 cm tall.