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Finding the Fourth Proportional to 687.80, 949 and 439.02

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Solution

The fourth proportional to 687.80, 949 and 439.02 is: 605.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    687.80 : 949 = 439.02 : x
  2. Step 2: Convert to fraction form
    687.80/949 = 439.02/x
  3. Step 3: Cross multiply
    687.80x = 949 × 439.02
  4. Step 4: Simplify right side
    687.80x = 416,629.98
  5. Step 5: Solve for x
    x = 416,629.98/687.80
  6. Step 6: Final answer
    x = 605.74

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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.