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Finding the Fourth Proportional to 856.78, 1,180.62 and 620.30

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Solution

The fourth proportional to 856.78, 1,180.62 and 620.30 is: 854.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    856.78 : 1,180.62 = 620.30 : x
  2. Step 2: Convert to fraction form
    856.78/1,180.62 = 620.30/x
  3. Step 3: Cross multiply
    856.78x = 1,180.62 × 620.30
  4. Step 4: Simplify right side
    856.78x = 732,338.59
  5. Step 5: Solve for x
    x = 732,338.59/856.78
  6. Step 6: Final answer
    x = 854.76

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.