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Finding the Fourth Proportional to 620.40, 930.60 and 550.80

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Solution

The fourth proportional to 620.40, 930.60 and 550.80 is: 826.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    620.40 : 930.60 = 550.80 : x
  2. Step 2: Convert to fraction form
    620.40/930.60 = 550.80/x
  3. Step 3: Cross multiply
    620.40x = 930.60 × 550.80
  4. Step 4: Simplify right side
    620.40x = 512,574.48
  5. Step 5: Solve for x
    x = 512,574.48/620.40
  6. Step 6: Final answer
    x = 826.20

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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.