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Finding the Fourth Proportional to 678.78, 936.62 and 383.99

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Solution

The fourth proportional to 678.78, 936.62 and 383.99 is: 529.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    678.78 : 936.62 = 383.99 : x
  2. Step 2: Convert to fraction form
    678.78/936.62 = 383.99/x
  3. Step 3: Cross multiply
    678.78x = 936.62 × 383.99
  4. Step 4: Simplify right side
    678.78x = 359,648.03
  5. Step 5: Solve for x
    x = 359,648.03/678.78
  6. Step 6: Final answer
    x = 529.85

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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.