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Finding the Fourth Proportional to 489.40, 734.70 and 485.80

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Solution

The fourth proportional to 489.40, 734.70 and 485.80 is: 729.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    489.40 : 734.70 = 485.80 : x
  2. Step 2: Convert to fraction form
    489.40/734.70 = 485.80/x
  3. Step 3: Cross multiply
    489.40x = 734.70 × 485.80
  4. Step 4: Simplify right side
    489.40x = 356,917.26
  5. Step 5: Solve for x
    x = 356,917.26/489.40
  6. Step 6: Final answer
    x = 729.30

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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.