The first graph shows the number of students (boys and girls in thousands) in Grade 1 to Grade 5.

And the bar graph below shows the percentage share of five schools in the total students studying in that class.

Based on the information, if the boys to girls ratio in school D is 3 : 1, then the number of boys studying in School D is:

26250

Total number of students in grade 1 to grade 5 = 20 + 15 + 12 + 22 + 8 + 18 + 14 + 9 + 10 +12

= 140 thousand 

= 140000

Percentage of students in D = 25%

Number of students in school D = \(\frac{25 }{100}\) × 140000 = 35000

Ratio of Boys to Girls = 3 : 1

Number of boys in school in D = \(\frac{3 }{4}\) × 35000 = 26250