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Finding the Fourth Proportional to 981.02, 1,353.54 and 631.91

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Solution

The fourth proportional to 981.02, 1,353.54 and 631.91 is: 871.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    981.02 : 1,353.54 = 631.91 : x
  2. Step 2: Convert to fraction form
    981.02/1,353.54 = 631.91/x
  3. Step 3: Cross multiply
    981.02x = 1,353.54 × 631.91
  4. Step 4: Simplify right side
    981.02x = 855,321.21
  5. Step 5: Solve for x
    x = 855,321.21/981.02
  6. Step 6: Final answer
    x = 871.87

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.