Final answer:
Graham will have a total of $725.40 in his savings account after 6 months, as calculated using the simple interest formula with a principal of $720, an annual interest rate of 1.5%, and a time period of 0.5 years.
Step-by-step explanation:
To calculate the total amount that Graham will have in his savings account after 6 months, we need to use the simple interest formula i = prt, where i is the interest earned, p is the principal amount, r is the annual interest rate expressed as a decimal, and t is the time in years.
In this case, the principal p is $720, the annual interest rate r is 1.5% or 0.015 when expressed as a decimal, and the time t is 0.5 years (since 6 months is half a year).
To find the interest earned after 6 months:
Interest = Principal × rate × time
Interest = $720 × 0.015 × 0.5
= $5.40
To find the total amount after 6 months, we add the interest to the principal:
Total amount = Principal + Interest
Total amount = $720 + $5.40
= $725.40
Therefore, Graham will have a total of $725.40 in his savings account after 6 months.