ANSWER:
Explanation:
We have that the Arnolds family are going to save a nickel on the first day of the month and then double the amount each day.
One nickel is equal to $0.05, therefore, we can make an recursive formula, it is a geometric sequence where the initial value is 0.05 and the ratio is equal to 2, because it doubles every day, therefore:
Now, from the above we can deduce the explicit formula, since the next value will be double the previous value, therefore, the explicit formula would be:
Therefore, the correct answers are the 1st and 4th options.