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Finding the Fourth Proportional to 1,205.78, 1,807.10 and 620.29

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Solution

The fourth proportional to 1,205.78, 1,807.10 and 620.29 is: 929.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,205.78 : 1,807.10 = 620.29 : x
  2. Step 2: Convert to fraction form
    1,205.78/1,807.10 = 620.29/x
  3. Step 3: Cross multiply
    1,205.78x = 1,807.10 × 620.29
  4. Step 4: Simplify right side
    1,205.78x = 1,120,926.06
  5. Step 5: Solve for x
    x = 1,120,926.06/1,205.78
  6. Step 6: Final answer
    x = 929.63

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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.