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Finding the Fourth Proportional to 409.78, 565.70 and 279.47

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Solution

The fourth proportional to 409.78, 565.70 and 279.47 is: 385.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    409.78 : 565.70 = 279.47 : x
  2. Step 2: Convert to fraction form
    409.78/565.70 = 279.47/x
  3. Step 3: Cross multiply
    409.78x = 565.70 × 279.47
  4. Step 4: Simplify right side
    409.78x = 158,097.59
  5. Step 5: Solve for x
    x = 158,097.59/409.78
  6. Step 6: Final answer
    x = 385.81

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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.