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Finding the Fourth Proportional to 687.44, 948.68 and 491.28

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Solution

The fourth proportional to 687.44, 948.68 and 491.28 is: 677.98

Step by Step Solution

  1. Step 1: Write the proportion equation
    687.44 : 948.68 = 491.28 : x
  2. Step 2: Convert to fraction form
    687.44/948.68 = 491.28/x
  3. Step 3: Cross multiply
    687.44x = 948.68 × 491.28
  4. Step 4: Simplify right side
    687.44x = 466,067.51
  5. Step 5: Solve for x
    x = 466,067.51/687.44
  6. Step 6: Final answer
    x = 677.98

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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.