Предмет: Математика, автор: ЕваTUMBLER

среднее арифметическое четырех чисел равно 2,1 а среднее арифметическое трех других чисел 2,8. Найдите среднее арифметическое этих семи чисел. ПОЖАЛУЙСТА! ДАЮ 35 БАЛЛОВ!

Ответы

Автор ответа: fiofionina

Решение:
Сумма четырёх чисел равна:
4*2,1=8,4
Сумма трёх других чисел:
3*2,8=8,4
Средне-арифметическое семи чисел:
(8,4+8,4)/(4+3)=16,8/7=2,4

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