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Finding the Fourth Proportional to 142.90, 214.38 and 88.72

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Solution

The fourth proportional to 142.90, 214.38 and 88.72 is: 133.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    142.90 : 214.38 = 88.72 : x
  2. Step 2: Convert to fraction form
    142.90/214.38 = 88.72/x
  3. Step 3: Cross multiply
    142.90x = 214.38 × 88.72
  4. Step 4: Simplify right side
    142.90x = 19,019.79
  5. Step 5: Solve for x
    x = 19,019.79/142.90
  6. Step 6: Final answer
    x = 133.10

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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.