The formula for calculating ROI is as follows:

ROI$=\frac{CLV\text{N}\text{u}\text{m}\text{b}\text{e}\text{r}of\text{C}\text{u}\text{s}\text{t}\text{o}\text{m}\text{e}\text{r}\text{s}}{\text{M}\text{a}\text{r}\text{k}\text{e}\text{t}\text{i}\text{n}\text{g}\text{C}\text{o}\text{s}\text{t}\text{s}}100$

Using the information below, calculate the ROI for Silver Day Spa?

$CLV=$$$2100$

Number of Customers $=5,432$

Marketing Costs $=$$$63,968$