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Finding the Fourth Proportional to 689.49, 1,028.58 and 670.65

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Solution

The fourth proportional to 689.49, 1,028.58 and 670.65 is: 1,000.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    689.49 : 1,028.58 = 670.65 : x
  2. Step 2: Convert to fraction form
    689.49/1,028.58 = 670.65/x
  3. Step 3: Cross multiply
    689.49x = 1,028.58 × 670.65
  4. Step 4: Simplify right side
    689.49x = 689,817.18
  5. Step 5: Solve for x
    x = 689,817.18/689.49
  6. Step 6: Final answer
    x = 1,000.47

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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.