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Finding the Fourth Proportional to 486.65, 671.87 and 309.71

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Solution

The fourth proportional to 486.65, 671.87 and 309.71 is: 427.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    486.65 : 671.87 = 309.71 : x
  2. Step 2: Convert to fraction form
    486.65/671.87 = 309.71/x
  3. Step 3: Cross multiply
    486.65x = 671.87 × 309.71
  4. Step 4: Simplify right side
    486.65x = 208,082.27
  5. Step 5: Solve for x
    x = 208,082.27/486.65
  6. Step 6: Final answer
    x = 427.59

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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.