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Finding the Fourth Proportional to 486.29, 729.48 and 139.64

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Solution

The fourth proportional to 486.29, 729.48 and 139.64 is: 209.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    486.29 : 729.48 = 139.64 : x
  2. Step 2: Convert to fraction form
    486.29/729.48 = 139.64/x
  3. Step 3: Cross multiply
    486.29x = 729.48 × 139.64
  4. Step 4: Simplify right side
    486.29x = 101,861.46
  5. Step 5: Solve for x
    x = 101,861.46/486.29
  6. Step 6: Final answer
    x = 209.47

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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.