Сумма всех напряжений: (217+214+223+216+225+221+223+224+219+22) + (214+223+216+225+221+223+224+219+22) + (217+214+223+216+225+221+223+224+219+22) + (214+223+216+225+221+223+224+219+22) + (217+214+223+216+225+221+223+224+219+22) + (214+223+216+225+221+223+224+219+22) + (217+214+223+216+225+221+223+224+219+22) + (214+223+216+225+221+223+224+219+22) + (217+214+223+216+225+221+223+224+219+22) + (214+223+216+225+221+223+224+219+22) = 4398. Среднее арифметическое: 4398 / 20 = 219.9.