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Finding the Fourth Proportional to 208.29, 312.54 and 121.70

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Solution

The fourth proportional to 208.29, 312.54 and 121.70 is: 182.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    208.29 : 312.54 = 121.70 : x
  2. Step 2: Convert to fraction form
    208.29/312.54 = 121.70/x
  3. Step 3: Cross multiply
    208.29x = 312.54 × 121.70
  4. Step 4: Simplify right side
    208.29x = 38,037.13
  5. Step 5: Solve for x
    x = 38,037.13/208.29
  6. Step 6: Final answer
    x = 182.62

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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.