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Finding the Fourth Proportional to 518.21, 715.12 and 285.34

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Solution

The fourth proportional to 518.21, 715.12 and 285.34 is: 393.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    518.21 : 715.12 = 285.34 : x
  2. Step 2: Convert to fraction form
    518.21/715.12 = 285.34/x
  3. Step 3: Cross multiply
    518.21x = 715.12 × 285.34
  4. Step 4: Simplify right side
    518.21x = 204,052.34
  5. Step 5: Solve for x
    x = 204,052.34/518.21
  6. Step 6: Final answer
    x = 393.76

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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.