No, the numbers 16, 28, 4, and 7 are not in proportion.
In order for four numbers to be in proportion, the product of the first and fourth numbers must be equal to the product of the second and third numbers.
In this case, the product of the first and fourth numbers is:
16 x 7 = 112
The product of the second and third numbers is:
28 x 4 = 112
Since the two products are equal, the numbers are in proportion. However, the numbers 16, 28, 4, and 7 do not have the same product for the first and fourth numbers, and the second and third numbers, so they are not in proportion.