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Finding the Fourth Proportional to 518.70, 716.55 and 389.31

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Solution

The fourth proportional to 518.70, 716.55 and 389.31 is: 537.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    518.70 : 716.55 = 389.31 : x
  2. Step 2: Convert to fraction form
    518.70/716.55 = 389.31/x
  3. Step 3: Cross multiply
    518.70x = 716.55 × 389.31
  4. Step 4: Simplify right side
    518.70x = 278,960.08
  5. Step 5: Solve for x
    x = 278,960.08/518.70
  6. Step 6: Final answer
    x = 537.81

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.