Questions: The variance of a sample of 81 observations is 64 . The standard deviation of the sample is which of the following? a. 4,096 b. 6,561 c. 9 d. 8

Solution Steps

The standard deviation (\( \sigma \)) is the square root of the variance (\( \sigma^2 \)). Mathematically, this is expressed as: \[ \sigma = \sqrt{\sigma^2} \]

The variance of the sample is given as 64. Plugging this into the formula: \[ \sigma = \sqrt{64} \]

Taking the square root of 64: \[ \sigma = 8 \]

Final Answer