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Finding the Fourth Proportional to 811.25, 1,217.09 and 324.64

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Solution

The fourth proportional to 811.25, 1,217.09 and 324.64 is: 487.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    811.25 : 1,217.09 = 324.64 : x
  2. Step 2: Convert to fraction form
    811.25/1,217.09 = 324.64/x
  3. Step 3: Cross multiply
    811.25x = 1,217.09 × 324.64
  4. Step 4: Simplify right side
    811.25x = 395,116.10
  5. Step 5: Solve for x
    x = 395,116.10/811.25
  6. Step 6: Final answer
    x = 487.05

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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.