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Finding the Fourth Proportional to 687.09, 947.96 and 407.42

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Solution

The fourth proportional to 687.09, 947.96 and 407.42 is: 562.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    687.09 : 947.96 = 407.42 : x
  2. Step 2: Convert to fraction form
    687.09/947.96 = 407.42/x
  3. Step 3: Cross multiply
    687.09x = 947.96 × 407.42
  4. Step 4: Simplify right side
    687.09x = 386,214.65
  5. Step 5: Solve for x
    x = 386,214.65/687.09
  6. Step 6: Final answer
    x = 562.10

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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.