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Finding the Fourth Proportional to 819.61, 1,228.69 and 306.25

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Solution

The fourth proportional to 819.61, 1,228.69 and 306.25 is: 459.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    819.61 : 1,228.69 = 306.25 : x
  2. Step 2: Convert to fraction form
    819.61/1,228.69 = 306.25/x
  3. Step 3: Cross multiply
    819.61x = 1,228.69 × 306.25
  4. Step 4: Simplify right side
    819.61x = 376,286.31
  5. Step 5: Solve for x
    x = 376,286.31/819.61
  6. Step 6: Final answer
    x = 459.10

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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.