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Finding the Fourth Proportional to 371.80, 512.56 and 305.31

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Solution

The fourth proportional to 371.80, 512.56 and 305.31 is: 420.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    371.80 : 512.56 = 305.31 : x
  2. Step 2: Convert to fraction form
    371.80/512.56 = 305.31/x
  3. Step 3: Cross multiply
    371.80x = 512.56 × 305.31
  4. Step 4: Simplify right side
    371.80x = 156,489.69
  5. Step 5: Solve for x
    x = 156,489.69/371.80
  6. Step 6: Final answer
    x = 420.90

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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.