Can someone please solve this question with steps. the right answer for standard deviation is 6.21%. I need the steps without using excel sheet.

a. Volatility of Exchange Rate Movements. Assume you want to determine whether the monthly movements in the Polish zloty against the dollar are more volatile than monthly movements in some other currencies against the dollar. The zloty was valued at $.4602 on May 1, $.4709 on June 1, $.4888 on July 1, $.4406 on August 1, and $.4260 on September 1. Compute the standard deviation (a measure of volatility) of the zloty's monthly exchange rate movements. Show your calculation. a. Volatility of Exchange Rate Movements. Assume you want to determine whether the monthly movements in the Polish zloty against the dollar are more volatile than monthly movements in some other currencies against the dollar. The zloty was valued at $.4602 on May 1, $.4709 on June 1, $.4888 on July 1, $.4406 on August 1, and $.4260 on September 1. Compute the standard deviation (a measure of volatility) of the zloty's monthly exchange rate movements. Show your calculation