The following is a list of 4 measurements:

[tex]\[6, 7, 9, 20\][/tex]

Suppose that these 4 measurements are respectively labeled [tex]\[x_1, x_2, \ldots, x_4\][/tex]. Compute the following:

[tex]\[
\sum_{i=1}^4\left(x_i\right)^2
\][/tex]



Answer :

Let's proceed step-by-step to compute the sum of the squares of each measurement given.


First, label the measurements as follows:
- [tex]\( x_1 = 6 \)[/tex]
- [tex]\( x_2 = 7 \)[/tex]
- [tex]\( x_3 = 9 \)[/tex]
- [tex]\( x_4 = 20 \)[/tex]


We need to calculate:
[tex]\[ \sum_{i=1}^4 (x_i)^2 = x_1^2 + x_2^2 + x_3^2 + x_4^2 \][/tex]


Substitute the values of [tex]\( x_1, x_2, x_3, \)[/tex] and [tex]\( x_4 \)[/tex]:


[tex]\[ 6^2 + 7^2 + 9^2 + 20^2 \][/tex]


Now square each measurement:


[tex]\[ 6^2 = 36 \][/tex]
[tex]\[ 7^2 = 49 \][/tex]
[tex]\[ 9^2 = 81 \][/tex]
[tex]\[ 20^2 = 400 \][/tex]


Next, sum these squared values:


[tex]\[ 36 + 49 + 81 + 400 \][/tex]


Add them step-by-step:


[tex]\[ 36 + 49 = 85 \][/tex]
[tex]\[ 85 + 81 = 166 \][/tex]
[tex]\[ 166 + 400 = 566 \][/tex]


Therefore, the sum of the squares of the measurements is:


[tex]\[ \sum_{i=1}^4 (x_i)^2 = 566 \][/tex]