The calculated error for each individual data point is relatively large. The average is 0.49 and the range is 0.05.

There are several alternatives that may be used to state the error in Cd.

Half the range

The average is 0.49: the range is 0.05. The value of Cd is 0.49±0.03 where the error is half the range.

Mean range

The average is 0.49: the range is 0.05: there are six data points. The value of Cd is 0.49±0.01 where the error is Range/6: the mean range.

Average deviation (preferred)

The average is 0.49: the deviations are 0.02, 0.02, 0.01, 0.03, 0.01 and 0.0. There are six data points.

(S Deviations)/N = 0.09/6 = 0.015

The value of Cd is 0.49±0.02 where the error is the average deviation.