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Finding the Fourth Proportional to 981.38, 1,354.36 and 561.80

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Solution

The fourth proportional to 981.38, 1,354.36 and 561.80 is: 775.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    981.38 : 1,354.36 = 561.80 : x
  2. Step 2: Convert to fraction form
    981.38/1,354.36 = 561.80/x
  3. Step 3: Cross multiply
    981.38x = 1,354.36 × 561.80
  4. Step 4: Simplify right side
    981.38x = 760,879.45
  5. Step 5: Solve for x
    x = 760,879.45/981.38
  6. Step 6: Final answer
    x = 775.32

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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.