Question

green block then the red block​

Answer 1

Step-by-step explanation:

Let x

1

,x

2

,x

3

,x

4

be four observations.

According to question

4

x

1

+x

2

+x

3

+x

4

=20

⇒x

1

+x

2

+x

3

+x

4

=80

After adding ’c’ to each observation the new