What is the standard deviation for the data set?

138, 129, 145, 134, 142, 159, 153, 142, 127

Express your answer as a decimal to the nearest tenth.

Using a scientific calculator, the standard deviation is computed to be 10.5.

You can also use the formula for standard deviation √[Σ (x-ц) ^2/n-1].

ц = (138 + 129+145+134+142+159+153+142+127) / 9 = 141

Σ (x-ц) ^2 = 884

884/8 = 110.5

√110.5 = 10.5