The standard deviation in terms of n observations having deviations from mean dm can be written as

• A. <img src="/_files/images/electronics-and-communication-engineering/measurements-and-instrumentation/243-299-1.png">
• B. <img src="/_files/images/electronics-and-communication-engineering/measurements-and-instrumentation/243-299-2.png">
• C. <img src="/_files/images/electronics-and-communication-engineering/measurements-and-instrumentation/243-299-3.png">
• D. <img src="/_files/images/electronics-and-communication-engineering/measurements-and-instrumentation/243-299-4.png">