Providing for doubtful accounts

At the end of the current year, the accounts recervable account has a debit balance of $$1,117,000$ and sales for the year total $$12,670,000.$

a$.$ The allowance account before adjustment has a debit balance of $$15,100.$ Bad debt expense is estimated at $\frac{3}{4}$ of $1\%$ of sales.

c$.$ The allowance account before adjustment has a credit balance of $$8,300.$ Bad debt expense is estimated at $\frac{1}{2}$ of $1\%$ of sales.

Determine the amount of the adjusting entry to provide for doubtful accounts under each of the assumptions $($a through d$)$ listed above.

a$.$ $

b$.$ $

C$.$ $

d$.$ $