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Finding the Fourth Proportional to 142.68, 212.85 and 138.76

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Solution

The fourth proportional to 142.68, 212.85 and 138.76 is: 207.00

Step by Step Solution

  1. Step 1: Write the proportion equation
    142.68 : 212.85 = 138.76 : x
  2. Step 2: Convert to fraction form
    142.68/212.85 = 138.76/x
  3. Step 3: Cross multiply
    142.68x = 212.85 × 138.76
  4. Step 4: Simplify right side
    142.68x = 29,535.07
  5. Step 5: Solve for x
    x = 29,535.07/142.68
  6. Step 6: Final answer
    x = 207.00

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.