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Finding the Fourth Proportional to 745.20, 1,118.07 and 312.21

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Solution

The fourth proportional to 745.20, 1,118.07 and 312.21 is: 468.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    745.20 : 1,118.07 = 312.21 : x
  2. Step 2: Convert to fraction form
    745.20/1,118.07 = 312.21/x
  3. Step 3: Cross multiply
    745.20x = 1,118.07 × 312.21
  4. Step 4: Simplify right side
    745.20x = 349,072.63
  5. Step 5: Solve for x
    x = 349,072.63/745.20
  6. Step 6: Final answer
    x = 468.43

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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.