Question

The mean of \[10\] number is \[20\]. If \[5\] is subtracted from every number, what will be the new mean?

Answer 1

Hint: In this problem, we need to find the new mean values from the given situation that can be calculated to get the result.The sum of the numbers is the mean. It is simple to calculate: add all the numbers together, then divide by the number of numbers. To put it another way, the total is divided by the count. We use the formula, \[{\text{ Mean = }}\dfrac{{{\text{Sum of all data}}}}{{{\text{Number of data points}}}}\] for finding new mean.

Complete step by step solution:
In this problem,
The mean is \[20\]
The number is \[10\]
The sum of the number is mean by adding the given number for the mean times. So, we can get
Total sum \[ = 10 \times 20 = 200\]
If \[5\] is subtracted from every number then get the new mean value, we get
Mean subtraction is \[10 \times 5 = 50\] from the total sum,
\[200 - 50 = 150\]
To find the new mean from the subtract mean is divided by the number, we get
\[{\text{ Mean = }}\dfrac{{{\text{Sum of all data}}}}{{{\text{Number of data points}}}}\]
By calculating the new mean is new mean is the sum of all data is divided by number
 \[ = \dfrac{{150}}{{10}} = 15\]
Therefore, the new mean is \[15\].

Note: A mean is a data point that is the sum of all the data points in the collection. It is the arithmetic average of the data set, which is determined by adding all of the data points together and then dividing by the number of data points in the data set. In statistics, the most common approach for determining the centre of a data set is to use the mean. It's a very simple but crucial part of the process.