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Finding the Fourth Proportional to 418.78, 578.16 and 279.10

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Solution

The fourth proportional to 418.78, 578.16 and 279.10 is: 385.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    418.78 : 578.16 = 279.10 : x
  2. Step 2: Convert to fraction form
    418.78/578.16 = 279.10/x
  3. Step 3: Cross multiply
    418.78x = 578.16 × 279.10
  4. Step 4: Simplify right side
    418.78x = 161,364.46
  5. Step 5: Solve for x
    x = 161,364.46/418.78
  6. Step 6: Final answer
    x = 385.32

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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.