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Finding the Fourth Proportional to 485.86, 670.57 and 289.38

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Solution

The fourth proportional to 485.86, 670.57 and 289.38 is: 399.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    485.86 : 670.57 = 289.38 : x
  2. Step 2: Convert to fraction form
    485.86/670.57 = 289.38/x
  3. Step 3: Cross multiply
    485.86x = 670.57 × 289.38
  4. Step 4: Simplify right side
    485.86x = 194,049.55
  5. Step 5: Solve for x
    x = 194,049.55/485.86
  6. Step 6: Final answer
    x = 399.39

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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.