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Finding the Fourth Proportional to 689.21, 1,034.84 and 678.95

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Solution

The fourth proportional to 689.21, 1,034.84 and 678.95 is: 1,019.44

Step by Step Solution

  1. Step 1: Write the proportion equation
    689.21 : 1,034.84 = 678.95 : x
  2. Step 2: Convert to fraction form
    689.21/1,034.84 = 678.95/x
  3. Step 3: Cross multiply
    689.21x = 1,034.84 × 678.95
  4. Step 4: Simplify right side
    689.21x = 702,605.02
  5. Step 5: Solve for x
    x = 702,605.02/689.21
  6. Step 6: Final answer
    x = 1,019.44

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.