Final answer:
Approximately 90.15 grams of the radioactive substance will be present after 4 months.
Step-by-step explanation:
To find the quantity of the radioactive substance present after 4 months, we need to substitute the value of t with 4 in the given formula:
Q(t) = 2744(7^(-0.3t))
Q(4) = 2744(7^(-0.3*4))
Q(4) = 2744(7^(-1.2))
Q(4) = 2744(0.03284)
Q(4) = 90.1466 grams
Therefore, approximately 90.15 grams of the radioactive substance will be present after 4 months.