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Finding the Fourth Proportional to 78.14, 117.34 and 43.40

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Solution

The fourth proportional to 78.14, 117.34 and 43.40 is: 65.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    78.14 : 117.34 = 43.40 : x
  2. Step 2: Convert to fraction form
    78.14/117.34 = 43.40/x
  3. Step 3: Cross multiply
    78.14x = 117.34 × 43.40
  4. Step 4: Simplify right side
    78.14x = 5,092.74
  5. Step 5: Solve for x
    x = 5,092.74/78.14
  6. Step 6: Final answer
    x = 65.17

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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.