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Finding the Fourth Proportional to 742.21, 1,113.09 and 309.25

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Solution

The fourth proportional to 742.21, 1,113.09 and 309.25 is: 463.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    742.21 : 1,113.09 = 309.25 : x
  2. Step 2: Convert to fraction form
    742.21/1,113.09 = 309.25/x
  3. Step 3: Cross multiply
    742.21x = 1,113.09 × 309.25
  4. Step 4: Simplify right side
    742.21x = 344,223.08
  5. Step 5: Solve for x
    x = 344,223.08/742.21
  6. Step 6: Final answer
    x = 463.78

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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.