9.58 , 9.69

The mean of a set of numbers is the sum divided by the number of terms.

x‾=9.58+9.692

Add 9.58 and 9.69.

x‾=19.272

Divide 19.27 by 2.

x‾=9.635

The mean should be rounded to one more decimal place than the original data. If the original data were mixed, round to one decimal place more than the least precise.

x‾=9.635

Set up the formula for variance. The variance of a set of values is a measure of the spread of its values.

s2=∑i=1n(xi-xavg)2n-1

Set up the formula for variance for this set of numbers.

s=(9.58-9.635)2+(9.69-9.635)22-1

Simplify the numerator.

Subtract 9.635 from 9.58.

s=(-0.055)2+(9.69-9.635)22-1

Raise -0.055 to the power of 2.

s=0.003025+(9.69-9.635)22-1

Subtract 9.635 from 9.69.

s=0.003025+0.05522-1

Raise 0.055 to the power of 2.

s=0.003025+0.0030252-1

Add 0.003025 and 0.003025.

s=0.006052-1

s=0.006052-1

Simplify the expression.

Subtract 1 from 2.

s=0.006051

Divide 0.00605 by 1.

s=0.00605

s=0.00605

s=0.00605

Approximate the result.

s2≈0.006

Find the Variance 9.58 , 9.69