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Finding the Fourth Proportional to 431.75, 647.61 and 123.60

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Solution

The fourth proportional to 431.75, 647.61 and 123.60 is: 185.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    431.75 : 647.61 = 123.60 : x
  2. Step 2: Convert to fraction form
    431.75/647.61 = 123.60/x
  3. Step 3: Cross multiply
    431.75x = 647.61 × 123.60
  4. Step 4: Simplify right side
    431.75x = 80,044.60
  5. Step 5: Solve for x
    x = 80,044.60/431.75
  6. Step 6: Final answer
    x = 185.40

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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.