Ten cartons are taken at random from an automatic filling machine. The mean net weight of 10 cartons is 15.90 oz., and sum of square deviation is 0.276. Does the sample mean differ significantly from the intended weight of 18 oz. Two samples are 10 cows and 10 buffalos of same age was taken and data about their milk yield in liter per day was collected which is as under.

Cow

buffalos

Mean

12 liters

10 liters

Standard Deviation

3liters

4liters