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Finding the Fourth Proportional to 142.44, 214.68 and 139.20

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Solution

The fourth proportional to 142.44, 214.68 and 139.20 is: 209.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    142.44 : 214.68 = 139.20 : x
  2. Step 2: Convert to fraction form
    142.44/214.68 = 139.20/x
  3. Step 3: Cross multiply
    142.44x = 214.68 × 139.20
  4. Step 4: Simplify right side
    142.44x = 29,883.46
  5. Step 5: Solve for x
    x = 29,883.46/142.44
  6. Step 6: Final answer
    x = 209.80

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.