In the table we can calculate the change in everi interval so for the first one is:
[tex]10-5=5[/tex]for the second interval will be:
[tex]20-10=10[/tex]and for the therth interval is:
[tex]40-20=20[/tex]so now we calculate the average rat so:
[tex]\frac{4+10+20}{3}=11.33[/tex]