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Finding the Fourth Proportional to 687.36, 948.48 and 491.28

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Solution

The fourth proportional to 687.36, 948.48 and 491.28 is: 677.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    687.36 : 948.48 = 491.28 : x
  2. Step 2: Convert to fraction form
    687.36/948.48 = 491.28/x
  3. Step 3: Cross multiply
    687.36x = 948.48 × 491.28
  4. Step 4: Simplify right side
    687.36x = 465,969.25
  5. Step 5: Solve for x
    x = 465,969.25/687.36
  6. Step 6: Final answer
    x = 677.91

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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.