Hey, I am having the hardest time trying to understand how to calculate and answer these questions the right way. Can someone please help walk me through it so I can understand what I'm doing wrong? Thank you so so much in advance.

Required information P7-4 (Algo) Analyzing and Interpreting Income Manipulation Under the LIFO Inventory Method LO7-2, 7-3 [The following information applies to the questions displayed below.] Pacific Company sells electronic test equipment that it acquires from a foreign source. During the year, the inventory records reflected the following: Inventory is valued at cost using the LIFO inventory method. Required: 1. Complete the following income statement summary using the LIFO method and the periodic inventory system. Answer is complete but not entirely correct. 2. The management, for various reasons, is considering buying 20 additional units before December 31 year-end at $9,570 each. Restate the income statement (and ending inventory), assuming that this purchase is made on December 31 . Assume the LIFO method and the periodic inventory system are used by the company. Answer is complete but not entirely correct. 3a. How much did pretax income change because of the decision on December 31, current year? 3b. Assuming that the unit cost of test equipment is expected to continue to decline during the following year, is there any evidence of income manipulation? Complete this question by entering your answers in the tabs below. How much did pretax income change because of the decision on December 31 , current year? 3a. How much did pretax income change because of the decision on December 31 , current year? 3b. Assuming that the unit cost of test equipment is expected to continue to decline during the following year, is there any evidence of income manipulation? Complete this question by entering your answers in the tabs below. Assuming that the unit cost of test equipment is expected to continue to decline during the following year, is there any evidence of income manipulation