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Finding the Fourth Proportional to 427.58, 640.76 and 319.25

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Solution

The fourth proportional to 427.58, 640.76 and 319.25 is: 478.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    427.58 : 640.76 = 319.25 : x
  2. Step 2: Convert to fraction form
    427.58/640.76 = 319.25/x
  3. Step 3: Cross multiply
    427.58x = 640.76 × 319.25
  4. Step 4: Simplify right side
    427.58x = 204,557.83
  5. Step 5: Solve for x
    x = 204,557.83/427.58
  6. Step 6: Final answer
    x = 478.41

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.