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Finding the Fourth Proportional to 434.06, 645.50 and 420.39

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Solution

The fourth proportional to 434.06, 645.50 and 420.39 is: 625.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    434.06 : 645.50 = 420.39 : x
  2. Step 2: Convert to fraction form
    434.06/645.50 = 420.39/x
  3. Step 3: Cross multiply
    434.06x = 645.50 × 420.39
  4. Step 4: Simplify right side
    434.06x = 271,361.75
  5. Step 5: Solve for x
    x = 271,361.75/434.06
  6. Step 6: Final answer
    x = 625.17

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.