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Finding the Fourth Proportional to 278.91, 384.47 and 208.86

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Solution

The fourth proportional to 278.91, 384.47 and 208.86 is: 287.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    278.91 : 384.47 = 208.86 : x
  2. Step 2: Convert to fraction form
    278.91/384.47 = 208.86/x
  3. Step 3: Cross multiply
    278.91x = 384.47 × 208.86
  4. Step 4: Simplify right side
    278.91x = 80,299.36
  5. Step 5: Solve for x
    x = 80,299.36/278.91
  6. Step 6: Final answer
    x = 287.91

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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.