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Finding the Fourth Proportional to 891.19, 1,229.89 and 498.21

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Solution

The fourth proportional to 891.19, 1,229.89 and 498.21 is: 687.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    891.19 : 1,229.89 = 498.21 : x
  2. Step 2: Convert to fraction form
    891.19/1,229.89 = 498.21/x
  3. Step 3: Cross multiply
    891.19x = 1,229.89 × 498.21
  4. Step 4: Simplify right side
    891.19x = 612,743.50
  5. Step 5: Solve for x
    x = 612,743.50/891.19
  6. Step 6: Final answer
    x = 687.56

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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.