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Finding the Fourth Proportional to 420.98, 630.90 and 247.77

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Solution

The fourth proportional to 420.98, 630.90 and 247.77 is: 371.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.98 : 630.90 = 247.77 : x
  2. Step 2: Convert to fraction form
    420.98/630.90 = 247.77/x
  3. Step 3: Cross multiply
    420.98x = 630.90 × 247.77
  4. Step 4: Simplify right side
    420.98x = 156,318.09
  5. Step 5: Solve for x
    x = 156,318.09/420.98
  6. Step 6: Final answer
    x = 371.32

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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.