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Finding the Fourth Proportional to 485.78, 670.49 and 299.43

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Solution

The fourth proportional to 485.78, 670.49 and 299.43 is: 413.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    485.78 : 670.49 = 299.43 : x
  2. Step 2: Convert to fraction form
    485.78/670.49 = 299.43/x
  3. Step 3: Cross multiply
    485.78x = 670.49 × 299.43
  4. Step 4: Simplify right side
    485.78x = 200,764.82
  5. Step 5: Solve for x
    x = 200,764.82/485.78
  6. Step 6: Final answer
    x = 413.28

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.