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Finding the Fourth Proportional to 485.85, 670.81 and 393.00

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Solution

The fourth proportional to 485.85, 670.81 and 393.00 is: 542.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    485.85 : 670.81 = 393.00 : x
  2. Step 2: Convert to fraction form
    485.85/670.81 = 393.00/x
  3. Step 3: Cross multiply
    485.85x = 670.81 × 393.00
  4. Step 4: Simplify right side
    485.85x = 263,628.24
  5. Step 5: Solve for x
    x = 263,628.24/485.85
  6. Step 6: Final answer
    x = 542.61

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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.