Khilona earned scores of 97, 73 and 88 respectively in her first three examinations. If she scored 80 in the fourth examination, then her average score will be
increased by 1
increased by 1.5
decreased by 1
decreased by 1.5
Initial average = \(\dfrac{97+73+88}{3} = 86\).
New average = \(\dfrac{97+73+88+80}{4} = 84.5\).
Decrease = 86 - 84.5 = 1.5.