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Finding the Fourth Proportional to 745.39, 1,118.09 and 420.09

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Solution

The fourth proportional to 745.39, 1,118.09 and 420.09 is: 630.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    745.39 : 1,118.09 = 420.09 : x
  2. Step 2: Convert to fraction form
    745.39/1,118.09 = 420.09/x
  3. Step 3: Cross multiply
    745.39x = 1,118.09 × 420.09
  4. Step 4: Simplify right side
    745.39x = 469,698.43
  5. Step 5: Solve for x
    x = 469,698.43/745.39
  6. Step 6: Final answer
    x = 630.14

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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.