Perpetual inventory system: journal entries. At the beginning of 20X3, Beehler Company implemented a computerized perpetual inventory system. The following transactions occurred:

• Purchases on account: 500 units @ $4 = $2,000

• Sales on account: 300 units @ $5 = $1,500

• Purchases on account: 600 units @ $5 = $3,000

• Sales on account: 300 units @ $5 = $1,500

a. Prepare journal entries for the above purchases and sales.

b. Calculate the balance in the firm's Inventory account.