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Finding the Fourth Proportional to 447, 670.36 and 138.78

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Solution

The fourth proportional to 447, 670.36 and 138.78 is: 208.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    447 : 670.36 = 138.78 : x
  2. Step 2: Convert to fraction form
    447/670.36 = 138.78/x
  3. Step 3: Cross multiply
    447x = 670.36 × 138.78
  4. Step 4: Simplify right side
    447x = 93,032.56
  5. Step 5: Solve for x
    x = 93,032.56/447
  6. Step 6: Final answer
    x = 208.13

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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.