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Finding the Fourth Proportional to 142.60, 213.54 and 78.34

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Solution

The fourth proportional to 142.60, 213.54 and 78.34 is: 117.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    142.60 : 213.54 = 78.34 : x
  2. Step 2: Convert to fraction form
    142.60/213.54 = 78.34/x
  3. Step 3: Cross multiply
    142.60x = 213.54 × 78.34
  4. Step 4: Simplify right side
    142.60x = 16,728.72
  5. Step 5: Solve for x
    x = 16,728.72/142.60
  6. Step 6: Final answer
    x = 117.31

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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.