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Finding the Fourth Proportional to 981.35, 1,353.87 and 561.47

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Solution

The fourth proportional to 981.35, 1,353.87 and 561.47 is: 774.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    981.35 : 1,353.87 = 561.47 : x
  2. Step 2: Convert to fraction form
    981.35/1,353.87 = 561.47/x
  3. Step 3: Cross multiply
    981.35x = 1,353.87 × 561.47
  4. Step 4: Simplify right side
    981.35x = 760,161.01
  5. Step 5: Solve for x
    x = 760,161.01/981.35
  6. Step 6: Final answer
    x = 774.61

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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.