I think X= 5^3
Hoped this helped!
65/.25 = 260
65 can go into .25, 260 times.
Multiply the number of packages by the mean. Then subtract the two totals:
400 x 4 = 1600
500 x 5 = 2500
weight of 5th package = 2500 - 1600 = 900kg
answer: 900 kg
The atmospheric pressure is 14 lb/s^2 at sea level is the answer.