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Finding the Fourth Proportional to 420.26, 630.40 and 131.70

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Solution

The fourth proportional to 420.26, 630.40 and 131.70 is: 197.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.26 : 630.40 = 131.70 : x
  2. Step 2: Convert to fraction form
    420.26/630.40 = 131.70/x
  3. Step 3: Cross multiply
    420.26x = 630.40 × 131.70
  4. Step 4: Simplify right side
    420.26x = 83,023.68
  5. Step 5: Solve for x
    x = 83,023.68/420.26
  6. Step 6: Final answer
    x = 197.55

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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.