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Finding the Fourth Proportional to 687.10, 1,028.58 and 443.80

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Solution

The fourth proportional to 687.10, 1,028.58 and 443.80 is: 664.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    687.10 : 1,028.58 = 443.80 : x
  2. Step 2: Convert to fraction form
    687.10/1,028.58 = 443.80/x
  3. Step 3: Cross multiply
    687.10x = 1,028.58 × 443.80
  4. Step 4: Simplify right side
    687.10x = 456,483.80
  5. Step 5: Solve for x
    x = 456,483.80/687.10
  6. Step 6: Final answer
    x = 664.36

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.