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Finding the Fourth Proportional to 807.75, 1,211.63 and 260.39

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Solution

The fourth proportional to 807.75, 1,211.63 and 260.39 is: 390.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    807.75 : 1,211.63 = 260.39 : x
  2. Step 2: Convert to fraction form
    807.75/1,211.63 = 260.39/x
  3. Step 3: Cross multiply
    807.75x = 1,211.63 × 260.39
  4. Step 4: Simplify right side
    807.75x = 315,488.98
  5. Step 5: Solve for x
    x = 315,488.98/807.75
  6. Step 6: Final answer
    x = 390.58

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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.