Say we have a bunch of numbers like 9, 2, 5, 4, 12, 7, 8, 11. To calculate the standard deviation of those numbers: 1  1. 2  Work out the Mean (the simple average of the numbers). 3  2. Then for each number: subtract the Mean and square the result. 4  3. Then work out the mean of those squared differences.5  4. Take the square root of that and we are done!o calculate the standard deviation of those numbers: 1  1. 2  Work out the Mean (the simple average of the numbers). 3  2. Then for each number: subtract the Mean and square the result.
Best Answer: The .925 does mean sterling silver and the FB may be a Hallmark. You did not state what is on the medallion so I don't know where it was made. On some silver items the FB stands for Franz Bibus a Czech silversmith.
Been an electrician for 47 years. The definition of MCB is a miniature circuit breaker, it trips if there is a line to natural fault. Ill add some extra information about the different types.ou see the rcd's control 5 circuits each, if 1 of these circuits had an earth fault on it, the rcd will trip and 5 of them circuits will go off, which means you have to keep tripping in you're rcd with an mcb 1 at a time to see which circuit the fault is on.