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Finding the Fourth Proportional to 687.42, 1,030.32 and 398.25

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Solution

The fourth proportional to 687.42, 1,030.32 and 398.25 is: 596.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    687.42 : 1,030.32 = 398.25 : x
  2. Step 2: Convert to fraction form
    687.42/1,030.32 = 398.25/x
  3. Step 3: Cross multiply
    687.42x = 1,030.32 × 398.25
  4. Step 4: Simplify right side
    687.42x = 410,324.94
  5. Step 5: Solve for x
    x = 410,324.94/687.42
  6. Step 6: Final answer
    x = 596.91

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.