Final answer:
To find the missing number in the proportion __ : 5 :: 12 : 60, we can solve it by cross-multiplication. The missing number is 1.
Step-by-step explanation:
To find the missing number in the proportion __ : 5 :: 12 : 60, we can solve it by cross-multiplication. Cross-multiplication involves multiplying the two outer numbers and setting it equal to the product of the two inner numbers. In this case, we have __ * 60 = 5 * 12. Solving this equation, we get __ = (5 * 12) / 60 = 1.