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Finding the Fourth Proportional to 680.95, 939.72 and 401.28

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Solution

The fourth proportional to 680.95, 939.72 and 401.28 is: 553.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    680.95 : 939.72 = 401.28 : x
  2. Step 2: Convert to fraction form
    680.95/939.72 = 401.28/x
  3. Step 3: Cross multiply
    680.95x = 939.72 × 401.28
  4. Step 4: Simplify right side
    680.95x = 377,090.84
  5. Step 5: Solve for x
    x = 377,090.84/680.95
  6. Step 6: Final answer
    x = 553.77

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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.