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Finding the Fourth Proportional to 678.71, 1,012.10 and 672.55

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Solution

The fourth proportional to 678.71, 1,012.10 and 672.55 is: 1,002.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    678.71 : 1,012.10 = 672.55 : x
  2. Step 2: Convert to fraction form
    678.71/1,012.10 = 672.55/x
  3. Step 3: Cross multiply
    678.71x = 1,012.10 × 672.55
  4. Step 4: Simplify right side
    678.71x = 680,687.66
  5. Step 5: Solve for x
    x = 680,687.66/678.71
  6. Step 6: Final answer
    x = 1,002.91

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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.