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Finding the Fourth Proportional to 678.66, 1,011.72 and 668.13

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Solution

The fourth proportional to 678.66, 1,011.72 and 668.13 is: 996.02

Step by Step Solution

  1. Step 1: Write the proportion equation
    678.66 : 1,011.72 = 668.13 : x
  2. Step 2: Convert to fraction form
    678.66/1,011.72 = 668.13/x
  3. Step 3: Cross multiply
    678.66x = 1,011.72 × 668.13
  4. Step 4: Simplify right side
    678.66x = 675,960.48
  5. Step 5: Solve for x
    x = 675,960.48/678.66
  6. Step 6: Final answer
    x = 996.02

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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.