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Finding the Fourth Proportional to 711.21, 981.09 and 489.77

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Solution

The fourth proportional to 711.21, 981.09 and 489.77 is: 675.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    711.21 : 981.09 = 489.77 : x
  2. Step 2: Convert to fraction form
    711.21/981.09 = 489.77/x
  3. Step 3: Cross multiply
    711.21x = 981.09 × 489.77
  4. Step 4: Simplify right side
    711.21x = 480,509.68
  5. Step 5: Solve for x
    x = 480,509.68/711.21
  6. Step 6: Final answer
    x = 675.63

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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.