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Finding the Fourth Proportional to 431.60, 650.78 and 426.20

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Solution

The fourth proportional to 431.60, 650.78 and 426.20 is: 642.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    431.60 : 650.78 = 426.20 : x
  2. Step 2: Convert to fraction form
    431.60/650.78 = 426.20/x
  3. Step 3: Cross multiply
    431.60x = 650.78 × 426.20
  4. Step 4: Simplify right side
    431.60x = 277,362.44
  5. Step 5: Solve for x
    x = 277,362.44/431.60
  6. Step 6: Final answer
    x = 642.64

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.