Consider the data: 8, 3, 10, 13, 4, 6, 7, 7, 8, 8, 5. Calculate its mean. Class 8

Consider the data: 8, 3, 10, 13, 4, 6, 7, 7, 8, 8, 5. Calculate its mean. Class 8

Question 1.

Consider the data: 8, 3, 10, 13, 4, 6, 7, 7, 8, 8, 5. Calculate its mean. Class 8

Solution:

Mean = [latex]\frac{8+3+10+13+4+6+7+7+8+8+5}{11}[/latex]

= [latex]\frac{79}{11}[/latex] = 7.18.

Question 2.

Now, consider this data with every value increased by 10 : 18, 13, 20, 23, 14, 16, 17, 17, 18, 18, 15. What is its mean? Is there a quicker way to find out? Class 8

[Hint : Observe the following dot plots corresponding to the two data collections.]

Solution:

Mean

= [latex]\frac{18+13+20+23+14+16+17+17+18+18+15}{11}[/latex]

= [latex]\frac{189}{11}[/latex] = 17.18.

Now, [latex]\frac{189}{11}[/latex] - [latex]\frac{79}{11}[/latex] = [latex]\frac{110}{11}[/latex] = 10. Thus, the mean increases by the same fixed number 10.