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Finding the Fourth Proportional to 685.60, 1,028.88 and 625.12

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Solution

The fourth proportional to 685.60, 1,028.88 and 625.12 is: 938.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    685.60 : 1,028.88 = 625.12 : x
  2. Step 2: Convert to fraction form
    685.60/1,028.88 = 625.12/x
  3. Step 3: Cross multiply
    685.60x = 1,028.88 × 625.12
  4. Step 4: Simplify right side
    685.60x = 643,173.47
  5. Step 5: Solve for x
    x = 643,173.47/685.60
  6. Step 6: Final answer
    x = 938.12

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.