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Finding the Fourth Proportional to 144.20, 216.30 and 90.20

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Solution

The fourth proportional to 144.20, 216.30 and 90.20 is: 135.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    144.20 : 216.30 = 90.20 : x
  2. Step 2: Convert to fraction form
    144.20/216.30 = 90.20/x
  3. Step 3: Cross multiply
    144.20x = 216.30 × 90.20
  4. Step 4: Simplify right side
    144.20x = 19,510.26
  5. Step 5: Solve for x
    x = 19,510.26/144.20
  6. Step 6: Final answer
    x = 135.30

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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.