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Finding the Fourth Proportional to 807.84, 1,211.75 and 345.12

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Solution

The fourth proportional to 807.84, 1,211.75 and 345.12 is: 517.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    807.84 : 1,211.75 = 345.12 : x
  2. Step 2: Convert to fraction form
    807.84/1,211.75 = 345.12/x
  3. Step 3: Cross multiply
    807.84x = 1,211.75 × 345.12
  4. Step 4: Simplify right side
    807.84x = 418,197.43
  5. Step 5: Solve for x
    x = 418,197.43/807.84
  6. Step 6: Final answer
    x = 517.67

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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.