Do these ratios form a proportion?

48 large blankets to 1 small blanket

96 large blankets to 2 small blankets

Yes, these ratios form a proportion. This can be seen by simplifying both ratios to their simplest form:

48 large blankets to 1 small blanket simplifies to 48:1
96 large blankets to 2 small blankets simplifies to 48:1

Since both ratios simplify to the same ratio, they are proportional.