7.) By clusterring $7.04 + $5.95 + $6.08 + $5.06 + $6.12 = $6.00 + $6.00 + $6.00 + $6.00 + $6.00 = $30.00
8.) 9.3 + 8.7 + 8.91 + 9.052 = 9 + 9 + 9 + 9 = 36
9.) 37.6 + 44.1 + 41 + 39.1 = 40 + 40 + 40 + 40 = 160
In clustering method you look for a whole number usually ending with 0 which all the given numbers "clustered" around.
Answer:

Step-by-step explanation:
Given the expression 
Using law of indices: 

Also:13+8=21
Therefore:

Answer:
Look the square root up on the internet.
Step-by-step explanation:
The answer is 4/7. Hope this helps