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Finding the Fourth Proportional to 689.07, 1,031.43 and 678.36

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Solution

The fourth proportional to 689.07, 1,031.43 and 678.36 is: 1,015.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    689.07 : 1,031.43 = 678.36 : x
  2. Step 2: Convert to fraction form
    689.07/1,031.43 = 678.36/x
  3. Step 3: Cross multiply
    689.07x = 1,031.43 × 678.36
  4. Step 4: Simplify right side
    689.07x = 699,680.85
  5. Step 5: Solve for x
    x = 699,680.85/689.07
  6. Step 6: Final answer
    x = 1,015.40

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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.