How do you write square root of -20 using the imaginary i

How do i simply this radical expression?

Ranck the following in order from least precise to most precise

The table shows the distances travelled by a paper aeroplane. a. find the range and interquartile range of the data. the range is feet. the interquartile range is __feet. b. interpret the range and interquartile range of the data. __ feet the distances travelled by the paper aeroplane varied by no more than__ feet. the middle half of the distances travelled by the paper aeroplane varied by no more than __ feet.