Answer:
The mean carrying load of the beams tested is 908.7 pounds per square foot
Step-by-step explanation:
1. Data class 1: 860-879
Midpoint 1: M1=(860+879)/2=1,739/2→M1=869.5
Number of values in data class 1: n1=2
2. Data class 2: 880-899
Midpoint 2: M2=(880+899)/2=1,779/2→M2=889.5
Number of values in data class 2: n2=5
3. Data class 3: 900-919
Midpoint 3: M3=(900+919)/2=1,819/2→M3=909.5
Number of values in data class 3: n3=10
4. Data class 4: 920-939
Midpoint 4: M4=(920+939)/2=1,859/2→M4=929.5
Number of values in data class 4: n4=6
5. Data class 5: 940-959
Midpoint 5: M5=(940+959)/2=1,899/2→M5=949.5
Number of values in data class 5: n5=1
Mean=Sum(Mi*ni)/Sum(ni)
Mean=(M1*n1+M2*n2+M3*n3+M4*n4+M5*n5)/(n1+n2+n3+n4+n5)
Mean=(869.5*2+889.5*5+909.5*10+929.5*6+949.5*1)/(2+5+10+6+1)
Mean=(1,739+4,447.5+9,095+5,577+949.5)/(24)
Mean=(21,808)/(24)
Mean=908.6666666
Rounding to one decimal place:
Mean=908.7
