Positive infinity is going after three hope this helps
The answer would be $99.40
The answer for your question will be -13
Total depth of the bottom of the plate is 4 + 1 = 5
Force = limit(5,1) 62.5 *7* x * dx
= 437.5. Lim(5,1) x*dx
= 437.5(x^2/2)^5 , 1
= 437.5 x (5^2/2 - 1/2)
= 437.5 x 12
= 5,250 pounds