Statistics - Mean and Standard Deviation for Grouped Data

The diagram above is the cumulative frequency curve for the daily time spent surfing Facebook of \(250\) students.

1. Use the graph to find
   1. the median time spent surfing Facebook,[1]
   2. the number of students who spend more than \(20\) minutes a day surfing Facebook,[2]
   3. the \(90^{th}\) percentile,[2]
   4. the interquartile range.[2]
2. A second group of students have a higher median and a larger standard deviation. Describe how the cumulative frequency graph will differ from this given curve.[2]