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Finding the Fourth Proportional to 420.75, 631.14 and 132.21

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Solution

The fourth proportional to 420.75, 631.14 and 132.21 is: 198.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.75 : 631.14 = 132.21 : x
  2. Step 2: Convert to fraction form
    420.75/631.14 = 132.21/x
  3. Step 3: Cross multiply
    420.75x = 631.14 × 132.21
  4. Step 4: Simplify right side
    420.75x = 83,443.02
  5. Step 5: Solve for x
    x = 83,443.02/420.75
  6. Step 6: Final answer
    x = 198.32

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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.