Explanation:

- Let’s call the four numbers after subtracting x:

(19–x), (28–x), (55–x), (91–x)

- These numbers are said to be in proportion, so:

(19–x)/(28–x) = (55–x)/(91–x)

- Cross-multiplied:

(19–x)(91–x) = (28–x)(55–x)

- Expand both sides:

19×91 – 19x – 91x + x² = 28×55 – 28x – 55x + x²

1729 – 110x + x² = 1540 – 83x + x²

- x² cancels:

1729 – 110x = 1540 – 83x

1729 – 1540 = 110x – 83x

189 = 27x

x = 7

- Now let’s check which option is correct:

- Option 1: 8

- Option 2: 7

- Option 3: 9

- Option 4: 5

- Correct answer is Option 2, 7.