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Finding the Fourth Proportional to 826.90, 1,238.72 and 621.70

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Solution

The fourth proportional to 826.90, 1,238.72 and 621.70 is: 931.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    826.90 : 1,238.72 = 621.70 : x
  2. Step 2: Convert to fraction form
    826.90/1,238.72 = 621.70/x
  3. Step 3: Cross multiply
    826.90x = 1,238.72 × 621.70
  4. Step 4: Simplify right side
    826.90x = 770,112.22
  5. Step 5: Solve for x
    x = 770,112.22/826.90
  6. Step 6: Final answer
    x = 931.32

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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.