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Finding the Fourth Proportional to 420.21, 625.60 and 418.18

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Solution

The fourth proportional to 420.21, 625.60 and 418.18 is: 622.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.21 : 625.60 = 418.18 : x
  2. Step 2: Convert to fraction form
    420.21/625.60 = 418.18/x
  3. Step 3: Cross multiply
    420.21x = 625.60 × 418.18
  4. Step 4: Simplify right side
    420.21x = 261,613.41
  5. Step 5: Solve for x
    x = 261,613.41/420.21
  6. Step 6: Final answer
    x = 622.58

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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.