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Finding the Fourth Proportional to 153.12, 229.20 and 142.80

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Solution

The fourth proportional to 153.12, 229.20 and 142.80 is: 213.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    153.12 : 229.20 = 142.80 : x
  2. Step 2: Convert to fraction form
    153.12/229.20 = 142.80/x
  3. Step 3: Cross multiply
    153.12x = 229.20 × 142.80
  4. Step 4: Simplify right side
    153.12x = 32,729.76
  5. Step 5: Solve for x
    x = 32,729.76/153.12
  6. Step 6: Final answer
    x = 213.75

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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.