Let the original bill be
, then the final bill after the charges been added are
, where
is the increase in the bill by 0.2 (100%+20% = 120% = 1.2)
The range of the original bill is
200 <
< 800, subtract each term by 25
175 <
< 775, divide each term by
145.83 <
< 645.83
Hence, the range of the original bill is between $145.83 and $645.83
If the are equal then they can be similar, otherwise they are not.
The best measure of center tendency for this set of data would be the median. It is the best measurement because the data set has an outlier. The outlier is the 30. So to find the median we first order the data set and then find out if the set is an even or odd set. This set is even so we just chose the middle number. If the set was even, we would add the two center number and divide them by 2.
3, 3, 4, 4, 4, 5, 5, 5, 30
The center tendency = 4