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Finding the Fourth Proportional to 807.98, 1,212.21 and 260.15

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Solution

The fourth proportional to 807.98, 1,212.21 and 260.15 is: 390.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    807.98 : 1,212.21 = 260.15 : x
  2. Step 2: Convert to fraction form
    807.98/1,212.21 = 260.15/x
  3. Step 3: Cross multiply
    807.98x = 1,212.21 × 260.15
  4. Step 4: Simplify right side
    807.98x = 315,356.43
  5. Step 5: Solve for x
    x = 315,356.43/807.98
  6. Step 6: Final answer
    x = 390.30

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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.