Most sample surveys use random digit dialing equipment to call residential telephone numbers at random. the telephone polling firm zogby international reports that the probability that a call reaches a live person is 0.15. calls are independent. (a) a polling firm places 7 calls. what is the probability that none of them reaches a person?

You have a 32-foot fence around a square garden. there are 4 equal sections. you paint 13 of one section of the fence. what fraction of the fence did you paint? you have a 32-foot fence around a square garden. there are 4 equal sections. you paint 13 of one section of the fence. what fraction of the fence did you paint?

Marina baked cookies. she gave 3/4 of the cookies to the scout bake sale. she shared the remaining 6 cookies with her friends. how many cookies did marina bake?

Astudent draws two parabolas on graph paper. both parabolas cross the x-axis at (–4, 0) and (6, 0). the y-intercept of the first parabola is (0, –12). the y-intercept of the second parabola is (0, –24). what is the positive difference between the a values for the two functions that describe the parabolas? write your answer as a decimal rounded to the nearest tenth