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Finding the Fourth Proportional to 989.96, 1,486.08 and 579.39

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Solution

The fourth proportional to 989.96, 1,486.08 and 579.39 is: 869.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    989.96 : 1,486.08 = 579.39 : x
  2. Step 2: Convert to fraction form
    989.96/1,486.08 = 579.39/x
  3. Step 3: Cross multiply
    989.96x = 1,486.08 × 579.39
  4. Step 4: Simplify right side
    989.96x = 861,019.89
  5. Step 5: Solve for x
    x = 861,019.89/989.96
  6. Step 6: Final answer
    x = 869.76

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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.