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Finding the Fourth Proportional to 687.79, 949.15 and 393.23

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Solution

The fourth proportional to 687.79, 949.15 and 393.23 is: 542.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    687.79 : 949.15 = 393.23 : x
  2. Step 2: Convert to fraction form
    687.79/949.15 = 393.23/x
  3. Step 3: Cross multiply
    687.79x = 949.15 × 393.23
  4. Step 4: Simplify right side
    687.79x = 373,227.54
  5. Step 5: Solve for x
    x = 373,227.54/687.79
  6. Step 6: Final answer
    x = 542.65

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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.