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Finding the Fourth Proportional to 506.40, 698.78 and 285.38

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Solution

The fourth proportional to 506.40, 698.78 and 285.38 is: 393.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    506.40 : 698.78 = 285.38 : x
  2. Step 2: Convert to fraction form
    506.40/698.78 = 285.38/x
  3. Step 3: Cross multiply
    506.40x = 698.78 × 285.38
  4. Step 4: Simplify right side
    506.40x = 199,420.00
  5. Step 5: Solve for x
    x = 199,420.00/506.40
  6. Step 6: Final answer
    x = 393.80

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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.