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Finding the Fourth Proportional to 505.78, 697.88 and 284.72

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Solution

The fourth proportional to 505.78, 697.88 and 284.72 is: 392.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    505.78 : 697.88 = 284.72 : x
  2. Step 2: Convert to fraction form
    505.78/697.88 = 284.72/x
  3. Step 3: Cross multiply
    505.78x = 697.88 × 284.72
  4. Step 4: Simplify right side
    505.78x = 198,697.62
  5. Step 5: Solve for x
    x = 198,697.62/505.78
  6. Step 6: Final answer
    x = 392.86

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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.