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Finding the Fourth Proportional to 809.75, 1,214.96 and 398.88

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Solution

The fourth proportional to 809.75, 1,214.96 and 398.88 is: 598.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    809.75 : 1,214.96 = 398.88 : x
  2. Step 2: Convert to fraction form
    809.75/1,214.96 = 398.88/x
  3. Step 3: Cross multiply
    809.75x = 1,214.96 × 398.88
  4. Step 4: Simplify right side
    809.75x = 484,621.25
  5. Step 5: Solve for x
    x = 484,621.25/809.75
  6. Step 6: Final answer
    x = 598.48

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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.