Fire load (MJ/m2) is the heat energy that could bereleased per square meter of floor area by combustionof contents and the structure itself. The article 鈥淔ireLoads in Office Buildings鈥 (J. of Structural Engr.,
1997: 365鈥368) gave the following cumulative percentages(read from a graph) for fire loads in a sample of388 rooms:
Value0 150 300 450 600
Cumulative %0 19.3 37.6 62.7 77.5
Value750 900 1050 1200 1350
Cumulative %87.2 93.8 95.7 98.6 99.1
Value1500 1650 1800 1950
Cumulative %99.5 99.6 99.8 100.0
a. Construct a relative frequency histogram and commenton interesting features.
b. What proportion of fire loads are less than 600? At least 1200?
c. What proportion of the loads are between 600 and1200?