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Finding the Fourth Proportional to 678.66, 936.47 and 398.98

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Solution

The fourth proportional to 678.66, 936.47 and 398.98 is: 550.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    678.66 : 936.47 = 398.98 : x
  2. Step 2: Convert to fraction form
    678.66/936.47 = 398.98/x
  3. Step 3: Cross multiply
    678.66x = 936.47 × 398.98
  4. Step 4: Simplify right side
    678.66x = 373,632.80
  5. Step 5: Solve for x
    x = 373,632.80/678.66
  6. Step 6: Final answer
    x = 550.54

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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.