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Finding the Fourth Proportional to 775.40, 1,161.90 and 672.20

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Solution

The fourth proportional to 775.40, 1,161.90 and 672.20 is: 1,007.26

Step by Step Solution

  1. Step 1: Write the proportion equation
    775.40 : 1,161.90 = 672.20 : x
  2. Step 2: Convert to fraction form
    775.40/1,161.90 = 672.20/x
  3. Step 3: Cross multiply
    775.40x = 1,161.90 × 672.20
  4. Step 4: Simplify right side
    775.40x = 781,029.18
  5. Step 5: Solve for x
    x = 781,029.18/775.40
  6. Step 6: Final answer
    x = 1,007.26

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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.