A given Arithmetic progression consist of 3m terms, the sum of the first term;the next m term and the last term are given to be x, y and z respectfuly prove that (x-z)^2=4(y^2-xz)​

How many kilometers are equal to 5 miles? use 1 mile ≈ 1.61 kilometers. !

I’m stuck on this equation, anyone got the answer?

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.