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Finding the Fourth Proportional to 431.78, 647.28 and 157.82

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Solution

The fourth proportional to 431.78, 647.28 and 157.82 is: 236.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    431.78 : 647.28 = 157.82 : x
  2. Step 2: Convert to fraction form
    431.78/647.28 = 157.82/x
  3. Step 3: Cross multiply
    431.78x = 647.28 × 157.82
  4. Step 4: Simplify right side
    431.78x = 102,150.49
  5. Step 5: Solve for x
    x = 102,150.49/431.78
  6. Step 6: Final answer
    x = 236.58

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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.