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Finding the Fourth Proportional to 813.09, 1,218.03 and 423.35

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Solution

The fourth proportional to 813.09, 1,218.03 and 423.35 is: 634.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    813.09 : 1,218.03 = 423.35 : x
  2. Step 2: Convert to fraction form
    813.09/1,218.03 = 423.35/x
  3. Step 3: Cross multiply
    813.09x = 1,218.03 × 423.35
  4. Step 4: Simplify right side
    813.09x = 515,646.91
  5. Step 5: Solve for x
    x = 515,646.91/813.09
  6. Step 6: Final answer
    x = 634.18

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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.