What measure of spread would be most appropriate to measure the amount of money that college students spend on rent per month?

A-Median
B-Range
C-Standard Deviation
D-Interquartile Range

White shapes and black shapes are used in a game. some of the shapes are circles. while the rest are squares. the ratio of the number of white shapes to the number of black shapes is 5: 11. the ratio of the number of white cicrles to the number of white squares is 3: 7. the ratio of the number of black circles to the number of black squres is 3: 8. work out what fraction of all the shapes are circles.