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Finding the Fourth Proportional to 427.80, 640.36 and 319.32

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Solution

The fourth proportional to 427.80, 640.36 and 319.32 is: 477.98

Step by Step Solution

  1. Step 1: Write the proportion equation
    427.80 : 640.36 = 319.32 : x
  2. Step 2: Convert to fraction form
    427.80/640.36 = 319.32/x
  3. Step 3: Cross multiply
    427.80x = 640.36 × 319.32
  4. Step 4: Simplify right side
    427.80x = 204,479.76
  5. Step 5: Solve for x
    x = 204,479.76/427.80
  6. Step 6: Final answer
    x = 477.98

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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.