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Finding the Fourth Proportional to 485.90, 730.44 and 399.86

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Solution

The fourth proportional to 485.90, 730.44 and 399.86 is: 601.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    485.90 : 730.44 = 399.86 : x
  2. Step 2: Convert to fraction form
    485.90/730.44 = 399.86/x
  3. Step 3: Cross multiply
    485.90x = 730.44 × 399.86
  4. Step 4: Simplify right side
    485.90x = 292,073.74
  5. Step 5: Solve for x
    x = 292,073.74/485.90
  6. Step 6: Final answer
    x = 601.10

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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.