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Finding the Fourth Proportional to 431.70, 647.66 and 123.55

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Solution

The fourth proportional to 431.70, 647.66 and 123.55 is: 185.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    431.70 : 647.66 = 123.55 : x
  2. Step 2: Convert to fraction form
    431.70/647.66 = 123.55/x
  3. Step 3: Cross multiply
    431.70x = 647.66 × 123.55
  4. Step 4: Simplify right side
    431.70x = 80,015.35
  5. Step 5: Solve for x
    x = 80,015.35/431.70
  6. Step 6: Final answer
    x = 185.35

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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.