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Finding the Fourth Proportional to 807.47, 1,211.20 and 259.71

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Solution

The fourth proportional to 807.47, 1,211.20 and 259.71 is: 389.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    807.47 : 1,211.20 = 259.71 : x
  2. Step 2: Convert to fraction form
    807.47/1,211.20 = 259.71/x
  3. Step 3: Cross multiply
    807.47x = 1,211.20 × 259.71
  4. Step 4: Simplify right side
    807.47x = 314,557.02
  5. Step 5: Solve for x
    x = 314,557.02/807.47
  6. Step 6: Final answer
    x = 389.56

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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.