please show work and any formulas used

3. In the table below, estimate the Arithmetic Average, the Variance and Standard Deviation of the IMX returns for the years 2017-2019. Year 2017 2018 2019 Return 0.095 0.073 0.051 a. If the return variability was represented by a normat(beli shapedi distribution, what the Standard deviation is telling you? in the normal distribution chart below, write the range of returns you'd get with a 99% probability