Answer: 21.21 cm
Step-by-step explanation:
Given
length of diagonal on the square is 30 cm
Suppose a is the side length of the square
and length of diagonal is given as 
So,

Thus, the side length of the square is 21.21 cm
To find the mean absolute deviation of the data, start by finding the mean of the data set.
Find the sum of the data values, and divide the sum by the number of data values.
Find the absolute value of the difference between each data value and the mean: ...
Find the sum of the absolute values of the differences
351 members
Multiply .65 by 540 which gives you 351.
Whats the question? how many is she buying? or how many can she afford?