Required:

a$.$ A decision by Cosmo Inc. to close the Town Store would result in a monthly increase $($decrease$)$ in Cosmo's operating income during next year of how much?

b$.$ Cosmo is considering a promotional campaign at the Town Store that would not affect the Mall Store. Increasing monthly promotional expenses at the Town Store by $$5,000$ in order to increase Town Store sales by $10$ percent would result in a monthly increase $($decrease$)$ in Cosmo's operating income during next year of how much?

c$.$ Half of Town Store's dollar sales are from items sold at variable cost to attract customers to the store. Cosmo is considering deleting these items, a move that would reduce the Town Store's direct fixed expenses by $15$ percent and result in the loss of $20$ percent of Town Store's remaining sales volume. This change would not affect the Mall Store. A decision to eliminate the items sold at cost would result in a monthly increase $($decrease$)$ in Cosmo's operating income during next year of how much?