Final answer:
To complete the equivalent proportion a:8=?, cross-multiply and solve for the missing ratio. The missing ratio can be found by ? = (8 * b) / a, where a:b is the given proportion and the missing ratio is denoted by ?. Substitute the values and calculate the missing ratio.
Step-by-step explanation:
To complete the equivalent proportion a:8=?, we need to find the missing ratio. The given proportion is ab=815. This means that the two ratios in the proportion are a:b and 8:? The unknown ratio, denoted by ?, can be found by cross-multiplying and solving for it. Cross-multiplying gives us a * ? = 8 * b. Rearranging the equation, we have ? = (8 * b) / a. Substituting the values from the given proportion, we get ? = (8 * 815) / a. Therefore, the ratio that completes the equivalent proportion a:8=? is (8 * 815) / a.