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Finding the Fourth Proportional to 429.81, 644.72 and 121.70

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Solution

The fourth proportional to 429.81, 644.72 and 121.70 is: 182.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    429.81 : 644.72 = 121.70 : x
  2. Step 2: Convert to fraction form
    429.81/644.72 = 121.70/x
  3. Step 3: Cross multiply
    429.81x = 644.72 × 121.70
  4. Step 4: Simplify right side
    429.81x = 78,458.59
  5. Step 5: Solve for x
    x = 78,458.59/429.81
  6. Step 6: Final answer
    x = 182.54

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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.