The ratio of the number of girls to the number of boys in a classroom 6:5. After 16 girls left the room, the ratio became 2:3. How many girls were there at first?

Ageologist had two rocks on a scale that weighed 4.6 kilograms together.rock a was 0.5 of the total weight.how much did rock a weigh?

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.

Simplify -4z+2y-y+-18z a.-22z+y b.-14z+2 c.3y+22z d.y +14z