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Finding the Fourth Proportional to 815.08, 1,221.66 and 522.20

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Solution

The fourth proportional to 815.08, 1,221.66 and 522.20 is: 782.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    815.08 : 1,221.66 = 522.20 : x
  2. Step 2: Convert to fraction form
    815.08/1,221.66 = 522.20/x
  3. Step 3: Cross multiply
    815.08x = 1,221.66 × 522.20
  4. Step 4: Simplify right side
    815.08x = 637,950.85
  5. Step 5: Solve for x
    x = 637,950.85/815.08
  6. Step 6: Final answer
    x = 782.68

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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.