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Finding the Fourth Proportional to 678.83, 936.79 and 399.07

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Solution

The fourth proportional to 678.83, 936.79 and 399.07 is: 550.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    678.83 : 936.79 = 399.07 : x
  2. Step 2: Convert to fraction form
    678.83/936.79 = 399.07/x
  3. Step 3: Cross multiply
    678.83x = 936.79 × 399.07
  4. Step 4: Simplify right side
    678.83x = 373,844.79
  5. Step 5: Solve for x
    x = 373,844.79/678.83
  6. Step 6: Final answer
    x = 550.72

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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.