Sew Good is a fashion apparel chain that sells a variety of clothes in California. Below are the actual demands and the forecasts that Sew Good recorded for 20 of their clothing designs from the past season. In the following problem round all the ratio values to 2 decimal places.

For example, use 0.97 instead of 0.9733 or 0.9689.

The point forecast for Sew Good's new "mood indigo" blue jeans the company plans to release in the coming season is 1450. Sew Good follows the forecast methodology we used in Session 4, and uses a normal distribution to forecast the demand for "mood indigo" jeans, and fits a demand model by studying the deviations of actual demands from forecasts in the last season using A/F ratios. What value of the descriptive standard deviation should Sew Good use for fitting the normal distribution? Please choose the closest number.