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Finding the Fourth Proportional to 687.21, 948.34 and 407.58

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Solution

The fourth proportional to 687.21, 948.34 and 407.58 is: 562.46

Step by Step Solution

  1. Step 1: Write the proportion equation
    687.21 : 948.34 = 407.58 : x
  2. Step 2: Convert to fraction form
    687.21/948.34 = 407.58/x
  3. Step 3: Cross multiply
    687.21x = 948.34 × 407.58
  4. Step 4: Simplify right side
    687.21x = 386,524.29
  5. Step 5: Solve for x
    x = 386,524.29/687.21
  6. Step 6: Final answer
    x = 562.46

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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.