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Finding the Fourth Proportional to 321.31, 440.53 and 315.47

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Solution

The fourth proportional to 321.31, 440.53 and 315.47 is: 432.52

Step by Step Solution

  1. Step 1: Write the proportion equation
    321.31 : 440.53 = 315.47 : x
  2. Step 2: Convert to fraction form
    321.31/440.53 = 315.47/x
  3. Step 3: Cross multiply
    321.31x = 440.53 × 315.47
  4. Step 4: Simplify right side
    321.31x = 138,974.31
  5. Step 5: Solve for x
    x = 138,974.31/321.31
  6. Step 6: Final answer
    x = 432.52

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.