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Finding the Fourth Proportional to 431.10, 645.57 and 286.38

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Solution

The fourth proportional to 431.10, 645.57 and 286.38 is: 428.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    431.10 : 645.57 = 286.38 : x
  2. Step 2: Convert to fraction form
    431.10/645.57 = 286.38/x
  3. Step 3: Cross multiply
    431.10x = 645.57 × 286.38
  4. Step 4: Simplify right side
    431.10x = 184,878.34
  5. Step 5: Solve for x
    x = 184,878.34/431.10
  6. Step 6: Final answer
    x = 428.85

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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.