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Finding the Fourth Proportional to 687.36, 949.86 and 521.28

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Solution

The fourth proportional to 687.36, 949.86 and 521.28 is: 720.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    687.36 : 949.86 = 521.28 : x
  2. Step 2: Convert to fraction form
    687.36/949.86 = 521.28/x
  3. Step 3: Cross multiply
    687.36x = 949.86 × 521.28
  4. Step 4: Simplify right side
    687.36x = 495,143.02
  5. Step 5: Solve for x
    x = 495,143.02/687.36
  6. Step 6: Final answer
    x = 720.35

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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.