+42 The five tallest buildings in Los Angeles in 1985 had a mean height of 733 feet. The tallest of the five buildings has a height of 858 feet, the shortest of the five 625 feet. If a new building were constructed with a height of 885 feet, by how many feet would it increase the mean height of the five tallest buildings of the city?
+129850 Call the total of the unknown bldg heights = x
So
625 + x + 858
____________ = 733
5
1483 + x = 733 (5)
1483 + x =3665 subtract 1483 from each side
x = 2182
When the new bldg is added the average is
858 + 2182 + 885
_________________ = 785
5
So the increase in the average is 785 - 733 = 52 ft
