Cynthia Knott's oyster bar buys fresh Louisiana oysters for

$$4$

per pound and sells them for

$$9$

per pound. Any oysters not sold that day are sold to her cousin, who has a nearby grocery store, for

$$3$

per pound. Cynthia believes that demand follows the normal distribution, with a mean of

$100$

pounds and a standard deviation of

$20$

pounds. How many pounds should she order each day? Refer to the

for z$-$values.