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Finding the Fourth Proportional to 485.76, 670.31 and 289.24

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Solution

The fourth proportional to 485.76, 670.31 and 289.24 is: 399.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    485.76 : 670.31 = 289.24 : x
  2. Step 2: Convert to fraction form
    485.76/670.31 = 289.24/x
  3. Step 3: Cross multiply
    485.76x = 670.31 × 289.24
  4. Step 4: Simplify right side
    485.76x = 193,879.02
  5. Step 5: Solve for x
    x = 193,879.02/485.76
  6. Step 6: Final answer
    x = 399.13

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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.