Standard deviation of the equivalent Celsius temperatures?

Question

If Y denotes a temperature recorded in degrees Fahrenheit, then (5/9)*(Y-32) is the corresponding temperature in degrees Celsius. If the standard deviation for a set of temperatures is 15.7 degrees Fahrenheit, what is the standard deviation of the equivalent Celsius temperature?

Is the answer a simple conversion from 15.7 degrees Fahrenheit to degrees Celsius? -9.055556 degrees Celsius??

Answer 1

Very close. If you leave out the 32 term, you will get the correct answer. In this problem, you are interested only in the relative size of the units and not the offset of the freezing point. And, just because I'm an engineer and picky about such things, if your most accurate number has three decimal places, don't offer more in your answer. Calculators lie.

Answer 2

The answer is c. 68 degrees F