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Finding the Fourth Proportional to 280.58, 387.02 and 209.64

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Solution

The fourth proportional to 280.58, 387.02 and 209.64 is: 289.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    280.58 : 387.02 = 209.64 : x
  2. Step 2: Convert to fraction form
    280.58/387.02 = 209.64/x
  3. Step 3: Cross multiply
    280.58x = 387.02 × 209.64
  4. Step 4: Simplify right side
    280.58x = 81,134.87
  5. Step 5: Solve for x
    x = 81,134.87/280.58
  6. Step 6: Final answer
    x = 289.17

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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.