Third derivative of xsinx? the answer key she gave us says it's -xcosx-3sinx. how?

James was playing a game with his friends. he won 35 points. then he lost 15, lost 40 and won 55. how did he come out

Aquadratic equation in standard from is written ax^2= bx+c, where a,b and c are real numbers and a is not zero?

3.17 scores on stats final. below are final exam scores of 20 introductory statistics students. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 57, 66, 69, 71, 72, 73, 74, 77, 78, 78, 79, 79, 81, 81, 82, 83, 83, 88, 89, 94 (a) the mean score is 77.7 points. with a standard deviation of 8.44 points. use this information to determine if the scores approximately follow the 68-95-99.7% rule. (b) do these data appear to follow a normal distribution? explain your reasoning using the graphs provided below.