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Finding the Fourth Proportional to 280.91, 420.49 and 256.99

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Solution

The fourth proportional to 280.91, 420.49 and 256.99 is: 384.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    280.91 : 420.49 = 256.99 : x
  2. Step 2: Convert to fraction form
    280.91/420.49 = 256.99/x
  3. Step 3: Cross multiply
    280.91x = 420.49 × 256.99
  4. Step 4: Simplify right side
    280.91x = 108,059.62
  5. Step 5: Solve for x
    x = 108,059.62/280.91
  6. Step 6: Final answer
    x = 384.68

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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.