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Finding the Fourth Proportional to 486, 668.25 and 420.39

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Solution

The fourth proportional to 486, 668.25 and 420.39 is: 578.04

Step by Step Solution

  1. Step 1: Write the proportion equation
    486 : 668.25 = 420.39 : x
  2. Step 2: Convert to fraction form
    486/668.25 = 420.39/x
  3. Step 3: Cross multiply
    486x = 668.25 × 420.39
  4. Step 4: Simplify right side
    486x = 280,925.62
  5. Step 5: Solve for x
    x = 280,925.62/486
  6. Step 6: Final answer
    x = 578.04

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.