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Finding the Fourth Proportional to 679.16, 1,020.11 and 405.79

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Solution

The fourth proportional to 679.16, 1,020.11 and 405.79 is: 609.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    679.16 : 1,020.11 = 405.79 : x
  2. Step 2: Convert to fraction form
    679.16/1,020.11 = 405.79/x
  3. Step 3: Cross multiply
    679.16x = 1,020.11 × 405.79
  4. Step 4: Simplify right side
    679.16x = 413,950.44
  5. Step 5: Solve for x
    x = 413,950.44/679.16
  6. Step 6: Final answer
    x = 609.50

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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.