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Finding the Fourth Proportional to 808.14, 1,212.21 and 519.78

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Solution

The fourth proportional to 808.14, 1,212.21 and 519.78 is: 779.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    808.14 : 1,212.21 = 519.78 : x
  2. Step 2: Convert to fraction form
    808.14/1,212.21 = 519.78/x
  3. Step 3: Cross multiply
    808.14x = 1,212.21 × 519.78
  4. Step 4: Simplify right side
    808.14x = 630,082.51
  5. Step 5: Solve for x
    x = 630,082.51/808.14
  6. Step 6: Final answer
    x = 779.67

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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.