Aschool administrator selects every 20th person on the list of names alphabetically to see what the favorite school subject is. is this biased?

Irene bought 3 yards of fabric and a spool of thread for $28.10. if the spool of thread cost $1.25, how much did the fabric cost per yard?

()1. how do you find range? 2.the following set of data is to be organized into a histogram. if there are to be five intervals on the graph, what should the length of each interval be? 30, 34, 23, 21, 27, 25, 29, 29, 25, 23, 32, 31

Asphere has a diameter of 10 in. what is the volume of the sphere?