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Finding the Fourth Proportional to 641.40, 961.26 and 486.87

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Solution

The fourth proportional to 641.40, 961.26 and 486.87 is: 729.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    641.40 : 961.26 = 486.87 : x
  2. Step 2: Convert to fraction form
    641.40/961.26 = 486.87/x
  3. Step 3: Cross multiply
    641.40x = 961.26 × 486.87
  4. Step 4: Simplify right side
    641.40x = 468,008.66
  5. Step 5: Solve for x
    x = 468,008.66/641.40
  6. Step 6: Final answer
    x = 729.67

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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.