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Finding the Fourth Proportional to 427.51, 641.33 and 138.88

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Solution

The fourth proportional to 427.51, 641.33 and 138.88 is: 208.33

Step by Step Solution

  1. Step 1: Write the proportion equation
    427.51 : 641.33 = 138.88 : x
  2. Step 2: Convert to fraction form
    427.51/641.33 = 138.88/x
  3. Step 3: Cross multiply
    427.51x = 641.33 × 138.88
  4. Step 4: Simplify right side
    427.51x = 89,064.01
  5. Step 5: Solve for x
    x = 89,064.01/427.51
  6. Step 6: Final answer
    x = 208.33

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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.