Three identical 180-day bank bills have been respectively sold to three investors at a price of $97,500 on 15/1/2017. After the purchase, these three investors have sold their bills at different yield rate on different dates to realise their capital gain/loss. Please see table 1 for their investment details.

Table 1: Investment details 

Investor's Name Selling date Capital gain/loss 

Adam 28/2/2017 $235 

Bill 14/3/2017 -$60 

Carl 15/2/2017 $170 

a. Calculate the purchase yield rate (simple interest rate).

b. Calculate the sale yield rate (simple interest) for each investor.

c. Use a Bar/Column chart to plot the results in part b.

Present your answers to the above questions in a functional Excel spreadsheet (it must be an XLSX or XLS file), giving each solution on a separate sheet (labelled Part a, Part b, and Part c). Your spreadsheet should be clearly labelled and easy to understand. Make sure you identify what the inputs and outputs are. Please include the necessary information e.g., title, axis titles and etc. in your plot. Use words to document your working steps.