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Finding the Fourth Proportional to 218.40, 327.75 and 90.15

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Solution

The fourth proportional to 218.40, 327.75 and 90.15 is: 135.29

Step by Step Solution

  1. Step 1: Write the proportion equation
    218.40 : 327.75 = 90.15 : x
  2. Step 2: Convert to fraction form
    218.40/327.75 = 90.15/x
  3. Step 3: Cross multiply
    218.40x = 327.75 × 90.15
  4. Step 4: Simplify right side
    218.40x = 29,546.66
  5. Step 5: Solve for x
    x = 29,546.66/218.40
  6. Step 6: Final answer
    x = 135.29

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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.