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Finding the Fourth Proportional to 980.11, 1,351.84 and 621.07

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Solution

The fourth proportional to 980.11, 1,351.84 and 621.07 is: 856.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    980.11 : 1,351.84 = 621.07 : x
  2. Step 2: Convert to fraction form
    980.11/1,351.84 = 621.07/x
  3. Step 3: Cross multiply
    980.11x = 1,351.84 × 621.07
  4. Step 4: Simplify right side
    980.11x = 839,592.06
  5. Step 5: Solve for x
    x = 839,592.06/980.11
  6. Step 6: Final answer
    x = 856.63

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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.