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Finding the Fourth Proportional to 426.86, 643.36 and 422.74

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Solution

The fourth proportional to 426.86, 643.36 and 422.74 is: 637.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    426.86 : 643.36 = 422.74 : x
  2. Step 2: Convert to fraction form
    426.86/643.36 = 422.74/x
  3. Step 3: Cross multiply
    426.86x = 643.36 × 422.74
  4. Step 4: Simplify right side
    426.86x = 271,974.01
  5. Step 5: Solve for x
    x = 271,974.01/426.86
  6. Step 6: Final answer
    x = 637.15

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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.