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Finding the Fourth Proportional to 678.39, 936.12 and 394.86

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Solution

The fourth proportional to 678.39, 936.12 and 394.86 is: 544.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    678.39 : 936.12 = 394.86 : x
  2. Step 2: Convert to fraction form
    678.39/936.12 = 394.86/x
  3. Step 3: Cross multiply
    678.39x = 936.12 × 394.86
  4. Step 4: Simplify right side
    678.39x = 369,636.34
  5. Step 5: Solve for x
    x = 369,636.34/678.39
  6. Step 6: Final answer
    x = 544.87

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.