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Finding the Fourth Proportional to 728.11, 1,090.22 and 418.38

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Solution

The fourth proportional to 728.11, 1,090.22 and 418.38 is: 626.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    728.11 : 1,090.22 = 418.38 : x
  2. Step 2: Convert to fraction form
    728.11/1,090.22 = 418.38/x
  3. Step 3: Cross multiply
    728.11x = 1,090.22 × 418.38
  4. Step 4: Simplify right side
    728.11x = 456,124.15
  5. Step 5: Solve for x
    x = 456,124.15/728.11
  6. Step 6: Final answer
    x = 626.45

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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.