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Finding the Fourth Proportional to 687.91, 949.27 and 393.19

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Solution

The fourth proportional to 687.91, 949.27 and 393.19 is: 542.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    687.91 : 949.27 = 393.19 : x
  2. Step 2: Convert to fraction form
    687.91/949.27 = 393.19/x
  3. Step 3: Cross multiply
    687.91x = 949.27 × 393.19
  4. Step 4: Simplify right side
    687.91x = 373,243.47
  5. Step 5: Solve for x
    x = 373,243.47/687.91
  6. Step 6: Final answer
    x = 542.58

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Double scale
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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.