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Finding the Fourth Proportional to 679.61, 1,019.15 and 289.79

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Solution

The fourth proportional to 679.61, 1,019.15 and 289.79 is: 434.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    679.61 : 1,019.15 = 289.79 : x
  2. Step 2: Convert to fraction form
    679.61/1,019.15 = 289.79/x
  3. Step 3: Cross multiply
    679.61x = 1,019.15 × 289.79
  4. Step 4: Simplify right side
    679.61x = 295,345.21
  5. Step 5: Solve for x
    x = 295,345.21/679.61
  6. Step 6: Final answer
    x = 434.58

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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.