This graph compares shoe sizes for a group of 80 two year olds boys and a group of 60 three year olds boys. About how many more two year olds boys have a shoe size of 6 or less, compared to the three year olds boys.
6
15
25
40

25

Step-by-step explanation:

each box represents 25% of the data presented

80 two year old boys were chosen for the study , half of 80 is 40

For the 3 year old boys,  the closest point to 6 is 6.5, and it is located after the line on the left.  This means that only 25% of the boys have shoe sizes of 6.5 or under.  25% of the 60 three-year olds they collected data on is 15.

The difference is 40-15= 25.

There are about 25 more two-year olds wearing a size 6 or under.

hope this helps

(b) 240

step-by-step explanation:

first, we use the pythagorean formula using the given side lengths to find x. then we use x to find the side lengths. then we add the side lengths to find the perimeter.

pythagorean theorem formula:

a^2 + b^2 = c^2

(x - 20)^2 + (x - 40)^2 = x^2

x^2 - 40x + 400 + x^2 - 80x + 1600 = x^2

x^2 -120x + 2000 = 0

(x - 100)(x - 20) = 0

x - 100 = 0 or x - 20 = 0

x = 100 or x = 20

we see that the solution x = 20 must be discarded because it will give a negative side length and a side length of 0. the only valid solution is x = 100.

perimeter = sum of the lengths of the sides

perimeter = x + x - 20 + x - 40

perimeter = 3x - 60

replace x with 100.

perimeter = 3(100) - 60

perimeter = 300 - 60

perimeter = 240