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Finding the Fourth Proportional to 208.48, 287.68 and 129.80

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Solution

The fourth proportional to 208.48, 287.68 and 129.80 is: 179.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    208.48 : 287.68 = 129.80 : x
  2. Step 2: Convert to fraction form
    208.48/287.68 = 129.80/x
  3. Step 3: Cross multiply
    208.48x = 287.68 × 129.80
  4. Step 4: Simplify right side
    208.48x = 37,340.86
  5. Step 5: Solve for x
    x = 37,340.86/208.48
  6. Step 6: Final answer
    x = 179.11

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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.