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Finding the Fourth Proportional to 678.06, 1,016.67 and 312.65

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Solution

The fourth proportional to 678.06, 1,016.67 and 312.65 is: 468.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    678.06 : 1,016.67 = 312.65 : x
  2. Step 2: Convert to fraction form
    678.06/1,016.67 = 312.65/x
  3. Step 3: Cross multiply
    678.06x = 1,016.67 × 312.65
  4. Step 4: Simplify right side
    678.06x = 317,856.79
  5. Step 5: Solve for x
    x = 317,856.79/678.06
  6. Step 6: Final answer
    x = 468.77

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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.