The constant rate of change of the account is $40 or Increasing by $40 per month.
Step-by-step explanation:
Consider the provided information.
Joanne is depositing money into a bank account. After 3 months there is $120 in the account. After 6 months there is $240 in the account.
Rate of change is known as how one quantity change in relation to other.
The rate of change can be calculated as:
y2-y1/x2-x1
Now use the above formula to calculated the rate of change.
240 - 120/6-3
120/3
40
Hence, the constant rate of change of the account is $40 or Increasing by $40 per month.