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Finding the Fourth Proportional to 809.10, 1,213.38 and 322.20

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Solution

The fourth proportional to 809.10, 1,213.38 and 322.20 is: 483.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    809.10 : 1,213.38 = 322.20 : x
  2. Step 2: Convert to fraction form
    809.10/1,213.38 = 322.20/x
  3. Step 3: Cross multiply
    809.10x = 1,213.38 × 322.20
  4. Step 4: Simplify right side
    809.10x = 390,951.04
  5. Step 5: Solve for x
    x = 390,951.04/809.10
  6. Step 6: Final answer
    x = 483.19

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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.