Question

Среднее арифметическое некоторого ряда данных, состочщего из 10 чисел, равно 7. К этому ряду приписали числа 17 и 18. Чему равно среднее арифметическое нового ряда чисел?

Answer 1

Найдем сумму 10 чисел: 
7*10=70
70+17+18= 105 - сумма 12 чисел

105:12 =8,75 - ср.ар нового ряда чисел

Answer 2

Calculation of the Average of the New Series

To calculate the average of the new series of numbers, we need to consider the original series of 10 numbers with an average of 7, and the two additional numbers, 17 and 18, that were added to the series.

The original series of 10 numbers has an average of 7. Let's denote this as A.

The sum of the original series can be calculated by multiplying the average by the number of elements in the series: Sum of the original series = Average * Number of elements = A * 10

Now, we need to calculate the sum of the new series, which includes the original series and the two additional numbers, 17 and 18.

The sum of the new series can be calculated by adding the sum of the original series to the sum of the two additional numbers: Sum of the new series = Sum of the original series + 17 + 18 = A * 10 + 17 + 18

To find the average of the new series, we divide the sum of the new series by the total number of elements in the new series, which is 12: Average of the new series = Sum of the new series / Number of elements = (A * 10 + 17 + 18) / 12

Now, let's substitute the value of the original series average, which is 7, into the equation: Average of the new series = (7 * 10 + 17 + 18) / 12

Calculating the expression: Average of the new series = (70 + 17 + 18) / 12 = 105 / 12 = 8.75

Therefore, the average of the new series of numbers is 8.75.