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Finding the Fourth Proportional to 500.78, 689.90 and 353.18

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Solution

The fourth proportional to 500.78, 689.90 and 353.18 is: 486.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    500.78 : 689.90 = 353.18 : x
  2. Step 2: Convert to fraction form
    500.78/689.90 = 353.18/x
  3. Step 3: Cross multiply
    500.78x = 689.90 × 353.18
  4. Step 4: Simplify right side
    500.78x = 243,658.88
  5. Step 5: Solve for x
    x = 243,658.88/500.78
  6. Step 6: Final answer
    x = 486.56

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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.