The bar shows the total number of students in four schools and it also shows the difference between boys and girls in these schools.

Find the ratio of 50% of total students in B and C to total boys in A and D.

The correct option is 27:44.

From the provided bar chart, we can extract the data for total students (Boys + Girls) represented by the blue bars and the difference between boys and girls (Boys - Girls) represented by the orange bars for each school:

School A: Total students (Boys + Girls) = 72, Difference (Boys - Girls) = 48
School B: Total students (Boys + Girls) = 60, Difference (Boys - Girls) = 28
School C: Total students (Boys + Girls) = 48, Difference (Boys - Girls) = 12
School D: Total students (Boys + Girls) = 52, Difference (Boys - Girls) = 4

Step 1: Calculate the total number of boys in schools A and D.
The number of boys in any school can be derived using the formula:

$\text{Boys}=\frac{\left(\text{Boys + Girls}\right)+\left(\text{Boys - Girls}\right)}{2}$

For School A:

$\text{Boys in A}=\frac{72+48}{2}=\frac{120}{2}=60$

For School D:

$\text{Boys in D}=\frac{52+4}{2}=\frac{56}{2}=28$

Total boys in School A and School D:

$\text{Total Boys (A + D)}=60+28=88$

Step 2: Calculate 50% of the total students in schools B and C.
Total students in School B = 60
Total students in School C = 48
Total students in schools B and C combined:

$\text{Total Students (B + C)}=60+48=108$

50% of total students in B and C:

$50\text{\% of}108=0.5\times 108=54$

Step 3: Find the required ratio.
Ratio of 50% of total students in B and C to total boys in A and D:

$\text{Ratio}=54:88=27:44$

Thus, the required ratio is 27:44.