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Finding the Fourth Proportional to 808.75, 1,215.39 and 479.84

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Solution

The fourth proportional to 808.75, 1,215.39 and 479.84 is: 721.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    808.75 : 1,215.39 = 479.84 : x
  2. Step 2: Convert to fraction form
    808.75/1,215.39 = 479.84/x
  3. Step 3: Cross multiply
    808.75x = 1,215.39 × 479.84
  4. Step 4: Simplify right side
    808.75x = 583,192.74
  5. Step 5: Solve for x
    x = 583,192.74/808.75
  6. Step 6: Final answer
    x = 721.11

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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.