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Finding the Fourth Proportional to 979.79, 1,469.90 and 486.47

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Solution

The fourth proportional to 979.79, 1,469.90 and 486.47 is: 729.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    979.79 : 1,469.90 = 486.47 : x
  2. Step 2: Convert to fraction form
    979.79/1,469.90 = 486.47/x
  3. Step 3: Cross multiply
    979.79x = 1,469.90 × 486.47
  4. Step 4: Simplify right side
    979.79x = 715,056.14
  5. Step 5: Solve for x
    x = 715,056.14/979.79
  6. Step 6: Final answer
    x = 729.81

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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.