The English coinage before decimalization included half-crowns (30 pennies), florins (24 pennies), shillings (12 pennies), sixpences (6 pennies), threepences (3 pennies) and pennies (1 penny). Show that with these coins the greedy algorithm does not necessarily produce an optimal solution even when an unlimited supply of coins of each denomination is available.

The stem-and-leaf plot shows the heights in centimeters of teddy bear sunflowers grown in two different types of soil. soil a soil b 5 9 5 2 1 1 6 3 9 5 1 0 7 0 2 3 6 7 8 2 1 8 3 0 9 key: 9|6 means 69 key: 5|8 means 58 calculate the mean of each data set. calculate the mean absolute deviation (mad) of each data set. which set is more variable? how do you know?