Annual Return, Annualised ROI & Determine Standard Deviation Calculation

Tom bought 5000 Apple shares on 18 september 2018,
On 25 August 2018, the board of directors of Apple announced a dividend of $0.20 per share to shareholders of record on 22 September 2018.

The figures below shows Apple’s return from year 2012 to 2017:
Year Returns
2012 26.4%
2013 9%
2014 3%
2015 13.6%
2016 -38.5%
2017 3.5%

a) Demonstrate your understanding by Calculating the average annual of return for Apple’s shares.

b) Demonstrate your understanding by calculating the annualised rate of return for Apple’s shares.

c) Demonstrate your understanding by determining the standard deviation of Apple’s returns over the six-year period and then interpret your answers.

Hint: Use ROI and make use of the 5 year return.