<image> A food factory draws a sample of 20 bags from its produced packaged food to test whether the weight of each bag meets the standard. The deviations from the standard, either exceeding or shortfall, are recorded as positive or negative numbers, respectively, as shown in the table.

Is the average weight of this batch of samples more or less than the standard weight? By how many grams is it more or less? If the standard weight is 450 grams, what is the total weight of the sampled bags?