What was the cause of civilization developing a division of labor

The arizona department of transportation wishes to survey state residents to determine what proportion of the population would like to increase statewide highway speed to 75 from 65 mph. at least how many residents do they need to survey if they want to be at least 99% confident that the sample proportion is within 0.09 of the true proportion?

What role did natural resources play in african politics?

Who is responsible for maintaining a balanced state budget