4.) An open box has a square base and a volume of 1331/2 in^3 . Find the dimensions of the box, assuming a minimum amount of 2 material is used in its construction.

a) The dimensions are 22in x 22in x 11/2in

b) The dimensions are in in 11/2in x 11in x 22in

c) The dimensions are in 11/2 in x 11/2in

d) The dimensions are in in 11in x 11in x 11/2in

e) The dimensions are in in 11in x 22in x 11in.

f) None of the above

5) Let f(x) = 5x^2+1, Compute the Riemann sum of f over the interval [0, 4] using 4 subintervals, choosing the right endpoints of the subintervals as representative points.

a) 74

b) 109

c) 155

d) 55

e) 154

f) None of the above

18.) The life expectancy of an electrical component has a probability density function that is defined by, f(t) = 1/2e^-0.5t, where t is given in months after the first use. Find the probability that a randomly selected component will last between 6 months and 12 months.

a) 0.0277

b) 0.0249

c) 0.9975

d) 0.0473

e) 0.0025

f) 0.9527

g) None of the above

Please answer all 3 thank you :)