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Finding the Fourth Proportional to 431.72, 647.49 and 123.49

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Solution

The fourth proportional to 431.72, 647.49 and 123.49 is: 185.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    431.72 : 647.49 = 123.49 : x
  2. Step 2: Convert to fraction form
    431.72/647.49 = 123.49/x
  3. Step 3: Cross multiply
    431.72x = 647.49 × 123.49
  4. Step 4: Simplify right side
    431.72x = 79,959.81
  5. Step 5: Solve for x
    x = 79,959.81/431.72
  6. Step 6: Final answer
    x = 185.21

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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.