Question 1190670
The range of the data set is:
 {{{Range = Highest Value - Lowest Value }}}

This is an indication of how wide 'spread' your data is. The higher the range. The farther apart your highest and lowest value (giving us information about the deviation of all the values from each other).


For this problem you will most likely want to put your data set into order:
"870.71, 924.8, 926.2, 927.0, 929.5, 930.3, 930.5, 934.3, 936.0, 938.5"


For (a) We take the Highest Value (938.5) and subtract this from the lowest value (870.71):
 {{{938.5-870.71 = 67.79 }}} 
 a) 67.79


For (b) We've been asked to change our data set, this now looks like: 
"807.71, 924.8, 926.2, 927.0, 929.5, 930.3, 930.5, 934.3, 936.0, 938.5"
We still calculate the range the same way (Highest - Lowest), but we now have a new lowest term:
 {{{938.5-807.71 = 130.79 }}}
 b) 130.79


By switching our lowest term we've almost doubled our range. This means that we can expect many more values (altitudes) from our experiment as it has a higher range.

I hope that helped! Good luck :^)