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Finding the Fourth Proportional to 486.39, 670.89 and 289.75

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Solution

The fourth proportional to 486.39, 670.89 and 289.75 is: 399.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    486.39 : 670.89 = 289.75 : x
  2. Step 2: Convert to fraction form
    486.39/670.89 = 289.75/x
  3. Step 3: Cross multiply
    486.39x = 670.89 × 289.75
  4. Step 4: Simplify right side
    486.39x = 194,388.93
  5. Step 5: Solve for x
    x = 194,388.93/486.39
  6. Step 6: Final answer
    x = 399.66

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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.