In year 2, Sammi Corp. changes its inventory method from FIFO to the weighted-average method. Under the weighted-average method, the year 2 beginning inventory is $3,000 higher than the FIFO method. The financial statements are revised using the retrospective approach. What are the financial statement effects of the change in accounting principle

The reason is that the opening inventory value of year 2 is the closing amount of the year 1. Its similar to the closing cash amount left in till at the end of year 1 which is the opening amount at the start of year 2. So the opening inventory of year 2 is closing inventory of year 1. So when we say that the opening inventory of year 2 has increased by $3,000 this means that the closing inventory of year 1 has increased by $3,000.

So now as we know that:

Cost of goods sold = Op. Inventory + Purchases - Cl. Inventory

This means if the closing amount increases the cost of goods decreases and in the given scenario the closing inventory of year 1 has been increased which means that the cost of goods sold has decreased by $3000 which will decrease the cost of goods sold and this will increase the profit with the same amount.

And if the profit increases then:

Earning per share = Profit after tax (Increased) / Number of share (Same)

According to the above formula if the profit has increased the earning per share will also increase.