Every person in a medical study is assigned a six-letter code, using only the letters A, B, C, and D. Which simulation tool(s) could be used to find the experimental probability that a code will have at least four A's? random number list
colored discs
coin
die

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