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Finding the Fourth Proportional to 279.64, 418.80 and 135.40

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Solution

The fourth proportional to 279.64, 418.80 and 135.40 is: 202.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    279.64 : 418.80 = 135.40 : x
  2. Step 2: Convert to fraction form
    279.64/418.80 = 135.40/x
  3. Step 3: Cross multiply
    279.64x = 418.80 × 135.40
  4. Step 4: Simplify right side
    279.64x = 56,705.52
  5. Step 5: Solve for x
    x = 56,705.52/279.64
  6. Step 6: Final answer
    x = 202.78

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.