Aphysics lab group was conducting an experiment to determine the length of a spring when different objects of varying weight were hung from it. after testing ten different objects, the group calculated the following linear regression where x is the weight of the object in ounces and h(x) is the length of the spring in centimeters: h(x)= 2.3x+15.5. what does y-intercept of this equation indicate about the relationship between object weight and the length of the spring?
1) when there is no object on the spring, its length is 2.3 cm
2) when there is no object on the spring, its length 15.5 cm
3) for every ounce of weight, the spring length increases by 2.3 cm
4) for every ounce of weight, the spring length increases by 1535 cm