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Finding the Fourth Proportional to 981.06, 1,353.78 and 631.50

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Solution

The fourth proportional to 981.06, 1,353.78 and 631.50 is: 871.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    981.06 : 1,353.78 = 631.50 : x
  2. Step 2: Convert to fraction form
    981.06/1,353.78 = 631.50/x
  3. Step 3: Cross multiply
    981.06x = 1,353.78 × 631.50
  4. Step 4: Simplify right side
    981.06x = 854,912.07
  5. Step 5: Solve for x
    x = 854,912.07/981.06
  6. Step 6: Final answer
    x = 871.42

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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.