Question

A student was performing an experiment that compared a new protein food to the old food for goldfish. He found the mean weight gain for the new food to be 12.8 grams with a standard deviation of 3.5 grams. Later he realized that the scale was out of calibration by 1.5 grams (meaning that the scale weighted items 1.5 grams too much). What should the mean and standard deviation be for the new food

Answer 1

Mean = 11.3 grams

Standard Deviation = 3.5 grams

Explanation:

Mean is affected by change of origin but standard deviation is not affected. Hence the scale weighed items 1.5 grams affect only the mean not standard deviation. Hence, the mean for new food item is 12.8 - 1.5 = 11.3 grams as weight gain by 1.5 gram due to wrong calibration and the standard deviation remains the same as 3.5 grams.