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Finding the Fourth Proportional to 981.72, 1,471.77 and 688.39

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Solution

The fourth proportional to 981.72, 1,471.77 and 688.39 is: 1,032.01

Step by Step Solution

  1. Step 1: Write the proportion equation
    981.72 : 1,471.77 = 688.39 : x
  2. Step 2: Convert to fraction form
    981.72/1,471.77 = 688.39/x
  3. Step 3: Cross multiply
    981.72x = 1,471.77 × 688.39
  4. Step 4: Simplify right side
    981.72x = 1,013,148.07
  5. Step 5: Solve for x
    x = 1,013,148.07/981.72
  6. Step 6: Final answer
    x = 1,032.01

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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.