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Finding the Fourth Proportional to 680.10, 1,019.78 and 289.98

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Solution

The fourth proportional to 680.10, 1,019.78 and 289.98 is: 434.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    680.10 : 1,019.78 = 289.98 : x
  2. Step 2: Convert to fraction form
    680.10/1,019.78 = 289.98/x
  3. Step 3: Cross multiply
    680.10x = 1,019.78 × 289.98
  4. Step 4: Simplify right side
    680.10x = 295,715.80
  5. Step 5: Solve for x
    x = 295,715.80/680.10
  6. Step 6: Final answer
    x = 434.81

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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.