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Finding the Fourth Proportional to 142.80, 214.15 and 51.49

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Solution

The fourth proportional to 142.80, 214.15 and 51.49 is: 77.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    142.80 : 214.15 = 51.49 : x
  2. Step 2: Convert to fraction form
    142.80/214.15 = 51.49/x
  3. Step 3: Cross multiply
    142.80x = 214.15 × 51.49
  4. Step 4: Simplify right side
    142.80x = 11,026.58
  5. Step 5: Solve for x
    x = 11,026.58/142.80
  6. Step 6: Final answer
    x = 77.22

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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.