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Finding the Fourth Proportional to 1,205.72, 1,808.76 and 620.40

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Solution

The fourth proportional to 1,205.72, 1,808.76 and 620.40 is: 930.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,205.72 : 1,808.76 = 620.40 : x
  2. Step 2: Convert to fraction form
    1,205.72/1,808.76 = 620.40/x
  3. Step 3: Cross multiply
    1,205.72x = 1,808.76 × 620.40
  4. Step 4: Simplify right side
    1,205.72x = 1,122,154.70
  5. Step 5: Solve for x
    x = 1,122,154.70/1,205.72
  6. Step 6: Final answer
    x = 930.69

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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.