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Finding the Fourth Proportional to 989.55, 1,487.97 and 747.09

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Solution

The fourth proportional to 989.55, 1,487.97 and 747.09 is: 1,123.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    989.55 : 1,487.97 = 747.09 : x
  2. Step 2: Convert to fraction form
    989.55/1,487.97 = 747.09/x
  3. Step 3: Cross multiply
    989.55x = 1,487.97 × 747.09
  4. Step 4: Simplify right side
    989.55x = 1,111,647.51
  5. Step 5: Solve for x
    x = 1,111,647.51/989.55
  6. Step 6: Final answer
    x = 1,123.39

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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.