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Finding the Fourth Proportional to 980.86, 1,352.87 and 621.83

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Solution

The fourth proportional to 980.86, 1,352.87 and 621.83 is: 857.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    980.86 : 1,352.87 = 621.83 : x
  2. Step 2: Convert to fraction form
    980.86/1,352.87 = 621.83/x
  3. Step 3: Cross multiply
    980.86x = 1,352.87 × 621.83
  4. Step 4: Simplify right side
    980.86x = 841,249.94
  5. Step 5: Solve for x
    x = 841,249.94/980.86
  6. Step 6: Final answer
    x = 857.67

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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.