The college bookstore sells a unique calculator to college students. the demand for this calculator has a normal distribution with an average daily demand of 20 units and a standard deviation of 4 units per day. the lead time for this calculator is 9 days. compute the statistical reorder point that results in a 95 percent in-stock probability. choose the closest answer. select one:
a. 200 units
b. 180 units
c. 420 units
d. 20 units
e. 80 units

Option (A) is correct.

Explanation:

Given that,

Mean daily demand, M = 20 calculators per day

Standard deviation, SD = 4 calculators per day

Lead time for this calculator, L = 9 days

z-critical value (for 95% in-stock probability) = 1.65 (From z tables)

Normal consumption during lead-time:

= Mean daily demand × Lead time

= 20 × 9

= 180 units of calculator

Safety Stock = z value × SD × L^(0.5)

                     = 1.65 × 4 × (9)^(0.5)

                     = 1.65 × 4 × 3

                     = 19.8 units

Reorder Point = Normal consumption during lead-time + Safety Stock

                        = 180 units  + 19.8 units

                        = 199.8 or 200 units (Approx)

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