Ashley, Trey, and job sent a total of 100 text messages during the weekend. Trey sent 10 more messages than ashely. Bob sent 3 times as many messages as Ashley. How many messages did they send ?

What is the missing step in this proof ?

Varies inversely with x. if y=8.5 when x=-1 find x when y=-1

Aresearch study is done to find the average age of all u. s. factory workers. the researchers asked every factory worker in ohio what their birth year is. this research is an example of a census survey convenience sample simple random sample