Which dot plot has the smallest range and tell me how to do range plz

Mean. (Average) add up all the data and divide by how many numbers there are.
Median. The middle number in a set of data that is in order from least to greatest.
Mode. ( most often) data value(s) that occur most often.
Range. 
Dot Plot. 
Line Plot. 
Find the mean. 
Find the range.

Mean (average) because it adds up the amount

First step is to get rid of the square root. remember that a square root is the same as raising to the (1/2) power. see below: multiply exponents per exponent rules to get: remember you subtract exponents from the denominator and add exponents in the numerator so: simplify further: so a is the correct choice. if you don't understand this google exponent rules and it will you understand. look at the image results.