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Finding the Fourth Proportional to 687.66, 948.74 and 407.98

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Solution

The fourth proportional to 687.66, 948.74 and 407.98 is: 562.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    687.66 : 948.74 = 407.98 : x
  2. Step 2: Convert to fraction form
    687.66/948.74 = 407.98/x
  3. Step 3: Cross multiply
    687.66x = 948.74 × 407.98
  4. Step 4: Simplify right side
    687.66x = 387,064.57
  5. Step 5: Solve for x
    x = 387,064.57/687.66
  6. Step 6: Final answer
    x = 562.88

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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.