Answer:
=IF(D15<1500, "Discontinue", "No Change")
Explanation:
In an Excel environment, you should navigate to cell F15 and apply the IF function. The structure of the IF function is
IF(<condition>, <value if true>, <value if false>)
Your condition is placed before the first comma, which is D15 < 1500.
The second segment, located before the second comma, is the text to display when D15 is below 1500, which is "Discontinue".
Finally, the last part should show text if D15 is 1500 or higher, which is "No Change".
The complete formula can be expressed as =IF(D15<1500, "Discontinue", "No Change")