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Finding the Fourth Proportional to 142.80, 214.20 and 97.20

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Solution

The fourth proportional to 142.80, 214.20 and 97.20 is: 145.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    142.80 : 214.20 = 97.20 : x
  2. Step 2: Convert to fraction form
    142.80/214.20 = 97.20/x
  3. Step 3: Cross multiply
    142.80x = 214.20 × 97.20
  4. Step 4: Simplify right side
    142.80x = 20,820.24
  5. Step 5: Solve for x
    x = 20,820.24/142.80
  6. Step 6: Final answer
    x = 145.80

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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.