Below is the net income of Blue Instrument Co., a private corporation, computed under the three inventory methods using a periodic system.

		FIFO		Average Cost		LIFO
2018		$25,900		$22,900		$19,900
2019		27,400		21,900		19,200
2020		29,200		27,400		24,200
2021		37,100		33,500		29,600

(Ignore tax considerations.) (a) Assume that in 2021 Blue decided to change from the FIFO method to the average-cost method of pricing inventories. Prepare the journal entry necessary for the change that took place during 2021, and show net income reported for 2018, 2019, 2020, and 2021.

(b) Assume that in 2021 Blue, which had been using the LIFO method since incorporation in 2018, changed to the FIFO method of pricing inventories. Prepare the journal entry necessary to record the change in 2021 and show net income reported for 2018, 2019, 2020, and 2021.