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Finding the Fourth Proportional to 419.90, 579.48 and 279.78

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Solution

The fourth proportional to 419.90, 579.48 and 279.78 is: 386.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    419.90 : 579.48 = 279.78 : x
  2. Step 2: Convert to fraction form
    419.90/579.48 = 279.78/x
  3. Step 3: Cross multiply
    419.90x = 579.48 × 279.78
  4. Step 4: Simplify right side
    419.90x = 162,126.91
  5. Step 5: Solve for x
    x = 162,126.91/419.90
  6. Step 6: Final answer
    x = 386.11

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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.