the average of 6 observations is 14 . a new observation is included and the new average is decreased by 1 . the seventh observation is ?
"let seventh observation = x . then , according to the question we have = > ( 84 + x ) / 7 = 13 = > x = 7 . hence , the seventh observation is 7 . answer : e"
subtract(multiply(subtract(14, 1), add(6, 1)), multiply(14, 6))