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Finding the Fourth Proportional to 685.50, 1,028.34 and 315.24

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Solution

The fourth proportional to 685.50, 1,028.34 and 315.24 is: 472.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    685.50 : 1,028.34 = 315.24 : x
  2. Step 2: Convert to fraction form
    685.50/1,028.34 = 315.24/x
  3. Step 3: Cross multiply
    685.50x = 1,028.34 × 315.24
  4. Step 4: Simplify right side
    685.50x = 324,173.90
  5. Step 5: Solve for x
    x = 324,173.90/685.50
  6. Step 6: Final answer
    x = 472.90

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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.