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Finding the Fourth Proportional to 648.40, 971.61 and 485.98

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Solution

The fourth proportional to 648.40, 971.61 and 485.98 is: 728.23

Step by Step Solution

  1. Step 1: Write the proportion equation
    648.40 : 971.61 = 485.98 : x
  2. Step 2: Convert to fraction form
    648.40/971.61 = 485.98/x
  3. Step 3: Cross multiply
    648.40x = 971.61 × 485.98
  4. Step 4: Simplify right side
    648.40x = 472,183.03
  5. Step 5: Solve for x
    x = 472,183.03/648.40
  6. Step 6: Final answer
    x = 728.23

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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.