Calculate the standard deviation if: LaTeX: \sum X\:=\:∑ X =159

LaTeX: \sum X^2∑ X 2= 3227

N = 12

36 girls

step-by-step explanation:

the 48 boys is 4 parts of the ratio

divide 48 by 4 to obtain one part of the ratio

= 12 ← 1 part of the ratio

3 parts = 3 × 12 = 36 ← number of girls

b) 1/3 * 1/5

step-by-step explanation:

each smallest part is 1/15 since the written one is 1/5 and it's divided by 3 equal parts. (1/5 )/3 = 1/15 = 1/3 * 1/5

the graph line crosses the x axis at both -6 and -2, so the answer would be the second one.