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Finding the Fourth Proportional to 280.40, 420.46 and 134.31

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Solution

The fourth proportional to 280.40, 420.46 and 134.31 is: 201.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    280.40 : 420.46 = 134.31 : x
  2. Step 2: Convert to fraction form
    280.40/420.46 = 134.31/x
  3. Step 3: Cross multiply
    280.40x = 420.46 × 134.31
  4. Step 4: Simplify right side
    280.40x = 56,470.86
  5. Step 5: Solve for x
    x = 56,470.86/280.40
  6. Step 6: Final answer
    x = 201.40

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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.