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Finding the Fourth Proportional to 498.80, 687.72 and 321.45

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Solution

The fourth proportional to 498.80, 687.72 and 321.45 is: 443.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    498.80 : 687.72 = 321.45 : x
  2. Step 2: Convert to fraction form
    498.80/687.72 = 321.45/x
  3. Step 3: Cross multiply
    498.80x = 687.72 × 321.45
  4. Step 4: Simplify right side
    498.80x = 221,067.59
  5. Step 5: Solve for x
    x = 221,067.59/498.80
  6. Step 6: Final answer
    x = 443.20

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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.