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Finding the Fourth Proportional to 680.61, 1,019.49 and 315.71

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Solution

The fourth proportional to 680.61, 1,019.49 and 315.71 is: 472.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    680.61 : 1,019.49 = 315.71 : x
  2. Step 2: Convert to fraction form
    680.61/1,019.49 = 315.71/x
  3. Step 3: Cross multiply
    680.61x = 1,019.49 × 315.71
  4. Step 4: Simplify right side
    680.61x = 321,863.19
  5. Step 5: Solve for x
    x = 321,863.19/680.61
  6. Step 6: Final answer
    x = 472.90

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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.