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Finding the Fourth Proportional to 989.09, 1,484.12 and 660.20

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Solution

The fourth proportional to 989.09, 1,484.12 and 660.20 is: 990.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    989.09 : 1,484.12 = 660.20 : x
  2. Step 2: Convert to fraction form
    989.09/1,484.12 = 660.20/x
  3. Step 3: Cross multiply
    989.09x = 1,484.12 × 660.20
  4. Step 4: Simplify right side
    989.09x = 979,818.60
  5. Step 5: Solve for x
    x = 979,818.60/989.09
  6. Step 6: Final answer
    x = 990.63

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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.