(a) In the given question,

We have to check if the given numbers are in proportion.

Now,

We know that,

A proportion happens when two ratios are forced to be equal to each other.

Thus,

And,

Therefore,

15 : 45 = 40 : 120

Hence,

We can clearly observe that,

The given numbers are in proportion.

(b) In the given question,

We have to check if the given numbers are in proportion.

Now,

We know that,

A proportion happens when two ratios are forced to be equal to each other.

Thus,

And,

Therefore,

33 : 121 ≠ 9 : 96

Hence,

We can clearly observe that,

The given numbers aren’t in proportion.

(c) In the given question,

We have to check if the given numbers are in proportion.

Now,

We know that,

A proportion happens when two ratios are forced to be equal to each other.

Thus,

And,

Therefore,

24 : 28 ≠ 36 : 48

Hence,

We can clearly observe that,

The given numbers are not in proportion.

(d) In the given question,

We have to check if the given numbers are in proportion.

Now,

We know that,

A proportion happens when two ratios are forced to be equal to each other.

Thus,

And,

Therefore,

32 : 48 ≠ 70 : 210

Hence,

We can clearly observe that,

The given numbers are not in proportion.

(e) In the given question,

We have to check if the given numbers are in proportion.

Now,

We know that,

A proportion happens when two ratios are forced to be equal to each other.

Thus,

And,

Therefore,

4 : 6 = 8 : 12

Hence,

We can clearly observe that,

The given numbers are in proportion.

(f) In the given question,

We have to check if the given numbers are in proportion.

Now,

We know that,

A proportion happens when two ratios are forced to be equal to each other.

Thus,

And,

Therefore,

33 : 44 = 75 : 100

Hence,

We can clearly observe that,

The given numbers are in proportion.