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Finding the Fourth Proportional to 816.28, 1,221.66 and 491.87

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Solution

The fourth proportional to 816.28, 1,221.66 and 491.87 is: 736.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    816.28 : 1,221.66 = 491.87 : x
  2. Step 2: Convert to fraction form
    816.28/1,221.66 = 491.87/x
  3. Step 3: Cross multiply
    816.28x = 1,221.66 × 491.87
  4. Step 4: Simplify right side
    816.28x = 600,900.96
  5. Step 5: Solve for x
    x = 600,900.96/816.28
  6. Step 6: Final answer
    x = 736.15

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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.