Final answer:
To calculate the amount in the account at the end of the third quarter, use the formula for compound interest. In this case, the amount is $940.70.
Step-by-step explanation:
To calculate the amount in the account at the end of the third quarter, we need to use the formula for compound interest: A = P(1 + r/n)^(nt), where A is the final amount, P is the principal, r is the interest rate, n is the number of times interest is compounded per year, and t is the number of years.
In this case, the principal is $900, the interest rate is 6% (or 0.06 as a decimal), and the interest is compounded quarterly (n = 4). We want to find the amount at the end of 3 quarters (t = 3/4).
Substituting these values into the formula:
A = 900(1 + 0.06/4)^(4 * 3/4) = 900(1.015)^3 = 900(1.045225) = $940.70
Therefore, the amount in the account at the end of the third quarter is $940.70.