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Finding the Fourth Proportional to 808.50, 1,212.69 and 260.55

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Solution

The fourth proportional to 808.50, 1,212.69 and 260.55 is: 390.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    808.50 : 1,212.69 = 260.55 : x
  2. Step 2: Convert to fraction form
    808.50/1,212.69 = 260.55/x
  3. Step 3: Cross multiply
    808.50x = 1,212.69 × 260.55
  4. Step 4: Simplify right side
    808.50x = 315,966.38
  5. Step 5: Solve for x
    x = 315,966.38/808.50
  6. Step 6: Final answer
    x = 390.81

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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.