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Finding the Fourth Proportional to 657.16, 906.40 and 420.90

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Solution

The fourth proportional to 657.16, 906.40 and 420.90 is: 580.53

Step by Step Solution

  1. Step 1: Write the proportion equation
    657.16 : 906.40 = 420.90 : x
  2. Step 2: Convert to fraction form
    657.16/906.40 = 420.90/x
  3. Step 3: Cross multiply
    657.16x = 906.40 × 420.90
  4. Step 4: Simplify right side
    657.16x = 381,503.76
  5. Step 5: Solve for x
    x = 381,503.76/657.16
  6. Step 6: Final answer
    x = 580.53

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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.