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Finding the Fourth Proportional to 815.15, 1,221.19 and 404.06

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Solution

The fourth proportional to 815.15, 1,221.19 and 404.06 is: 605.33

Step by Step Solution

  1. Step 1: Write the proportion equation
    815.15 : 1,221.19 = 404.06 : x
  2. Step 2: Convert to fraction form
    815.15/1,221.19 = 404.06/x
  3. Step 3: Cross multiply
    815.15x = 1,221.19 × 404.06
  4. Step 4: Simplify right side
    815.15x = 493,437.79
  5. Step 5: Solve for x
    x = 493,437.79/815.15
  6. Step 6: Final answer
    x = 605.33

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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.