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Finding the Fourth Proportional to 420.15, 630.12 and 131.59

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Solution

The fourth proportional to 420.15, 630.12 and 131.59 is: 197.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.15 : 630.12 = 131.59 : x
  2. Step 2: Convert to fraction form
    420.15/630.12 = 131.59/x
  3. Step 3: Cross multiply
    420.15x = 630.12 × 131.59
  4. Step 4: Simplify right side
    420.15x = 82,918.77
  5. Step 5: Solve for x
    x = 82,918.77/420.15
  6. Step 6: Final answer
    x = 197.35

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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.