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Finding the Fourth Proportional to 620.40, 930.61 and 255.20

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Solution

The fourth proportional to 620.40, 930.61 and 255.20 is: 382.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    620.40 : 930.61 = 255.20 : x
  2. Step 2: Convert to fraction form
    620.40/930.61 = 255.20/x
  3. Step 3: Cross multiply
    620.40x = 930.61 × 255.20
  4. Step 4: Simplify right side
    620.40x = 237,491.14
  5. Step 5: Solve for x
    x = 237,491.14/620.40
  6. Step 6: Final answer
    x = 382.80

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Similar ratio
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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.