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Finding the Fourth Proportional to 678.75, 936.63 and 398.94

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Solution

The fourth proportional to 678.75, 936.63 and 398.94 is: 550.51

Step by Step Solution

  1. Step 1: Write the proportion equation
    678.75 : 936.63 = 398.94 : x
  2. Step 2: Convert to fraction form
    678.75/936.63 = 398.94/x
  3. Step 3: Cross multiply
    678.75x = 936.63 × 398.94
  4. Step 4: Simplify right side
    678.75x = 373,659.17
  5. Step 5: Solve for x
    x = 373,659.17/678.75
  6. Step 6: Final answer
    x = 550.51

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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.