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Finding the Fourth Proportional to 678.84, 1,012.38 and 662.28

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Solution

The fourth proportional to 678.84, 1,012.38 and 662.28 is: 987.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    678.84 : 1,012.38 = 662.28 : x
  2. Step 2: Convert to fraction form
    678.84/1,012.38 = 662.28/x
  3. Step 3: Cross multiply
    678.84x = 1,012.38 × 662.28
  4. Step 4: Simplify right side
    678.84x = 670,479.03
  5. Step 5: Solve for x
    x = 670,479.03/678.84
  6. Step 6: Final answer
    x = 987.68

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.