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Finding the Fourth Proportional to 678.84, 940.72 and 665.88

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Solution

The fourth proportional to 678.84, 940.72 and 665.88 is: 922.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    678.84 : 940.72 = 665.88 : x
  2. Step 2: Convert to fraction form
    678.84/940.72 = 665.88/x
  3. Step 3: Cross multiply
    678.84x = 940.72 × 665.88
  4. Step 4: Simplify right side
    678.84x = 626,406.63
  5. Step 5: Solve for x
    x = 626,406.63/678.84
  6. Step 6: Final answer
    x = 922.76

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Why These Related Problems?

These problems maintain the same ratio (1.39) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.