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Finding the Fourth Proportional to 687.28, 1,030.84 and 254.40

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Solution

The fourth proportional to 687.28, 1,030.84 and 254.40 is: 381.57

Step by Step Solution

  1. Step 1: Write the proportion equation
    687.28 : 1,030.84 = 254.40 : x
  2. Step 2: Convert to fraction form
    687.28/1,030.84 = 254.40/x
  3. Step 3: Cross multiply
    687.28x = 1,030.84 × 254.40
  4. Step 4: Simplify right side
    687.28x = 262,245.70
  5. Step 5: Solve for x
    x = 262,245.70/687.28
  6. Step 6: Final answer
    x = 381.57

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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.