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Finding the Fourth Proportional to 420.19, 630.29 and 163.87

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Solution

The fourth proportional to 420.19, 630.29 and 163.87 is: 245.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.19 : 630.29 = 163.87 : x
  2. Step 2: Convert to fraction form
    420.19/630.29 = 163.87/x
  3. Step 3: Cross multiply
    420.19x = 630.29 × 163.87
  4. Step 4: Simplify right side
    420.19x = 103,285.62
  5. Step 5: Solve for x
    x = 103,285.62/420.19
  6. Step 6: Final answer
    x = 245.81

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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.