Final answer:
The net cash provided (used) by investing activities during 2018 is -$1,900,000.
Step-by-step explanation:
The net cash provided (used) by investing activities during 2018 can be calculated by summing up the cash inflows and subtracting the cash outflows. In this case, the cash inflows include the proceeds from issuing bonds ($3,000,000), the proceeds from issuing preferred stock ($1,600,000), and the proceeds from the sale of equipment ($300,000), which total $4,900,000. The cash outflows include the purchase of land by issuing bonds ($1,000,000), the purchases of inventory ($3,800,000), the purchases of treasury stock ($600,000), and the loans made to affiliated corporations ($1,400,000), which total $6,800,000. Therefore, the net cash provided (used) by investing activities during 2018 is $(6,800,000 - 4,900,000) = -$1,900,000.