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Finding the Fourth Proportional to 286.78, 430.26 and 142.42

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Solution

The fourth proportional to 286.78, 430.26 and 142.42 is: 213.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    286.78 : 430.26 = 142.42 : x
  2. Step 2: Convert to fraction form
    286.78/430.26 = 142.42/x
  3. Step 3: Cross multiply
    286.78x = 430.26 × 142.42
  4. Step 4: Simplify right side
    286.78x = 61,277.63
  5. Step 5: Solve for x
    x = 61,277.63/286.78
  6. Step 6: Final answer
    x = 213.67

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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.