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Finding the Fourth Proportional to 429.75, 643.68 and 418.23

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Solution

The fourth proportional to 429.75, 643.68 and 418.23 is: 626.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    429.75 : 643.68 = 418.23 : x
  2. Step 2: Convert to fraction form
    429.75/643.68 = 418.23/x
  3. Step 3: Cross multiply
    429.75x = 643.68 × 418.23
  4. Step 4: Simplify right side
    429.75x = 269,206.29
  5. Step 5: Solve for x
    x = 269,206.29/429.75
  6. Step 6: Final answer
    x = 626.43

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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.