Which study appears to look for an association between two variables without actively manipulating either one? what are those variables

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

Aretha wanted to gather data about the cost of local bowling leagues in her area. she plotted the data and determined that the average bowling league costs consist of a one-time registration fee and a monthly fee modeled by the equation y = 15x + 20. identify and interpret the y-intercept in this model. the y-intercept is 20. this is the cost per month. the y-intercept is 20. this is the cost of registration. the y-intercept is 15. this is the cost of registration. the y-intercept is 15. this is the cost per month.

Yolanda wanted to buy a total of 6 pounds of mixed nuts and dried fruit for a party she paid 21.60 for mixed nuts and 11.90 for dried fruit did yolanda but enough mixed nuts and dried fruit for the party