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Finding the Fourth Proportional to 427.88, 642.14 and 319.40

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Solution

The fourth proportional to 427.88, 642.14 and 319.40 is: 479.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    427.88 : 642.14 = 319.40 : x
  2. Step 2: Convert to fraction form
    427.88/642.14 = 319.40/x
  3. Step 3: Cross multiply
    427.88x = 642.14 × 319.40
  4. Step 4: Simplify right side
    427.88x = 205,099.52
  5. Step 5: Solve for x
    x = 205,099.52/427.88
  6. Step 6: Final answer
    x = 479.34

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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.