The average height of 10 students in a class is 78 cm. If the heights of 4 more students are included, then the average height increases to 80 cm. Find the sum of the heights of the new students.
1
240 cm
2
120 cm
3
340 cm
4
560 cm
The average height of 10 students in a class is 78 cm. If the heights of 4 more students are included, then the average height increases to 80 cm. Find the sum of the heights of the new students.