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Finding the Fourth Proportional to 78.96, 118.26 and 78.42

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Solution

The fourth proportional to 78.96, 118.26 and 78.42 is: 117.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    78.96 : 118.26 = 78.42 : x
  2. Step 2: Convert to fraction form
    78.96/118.26 = 78.42/x
  3. Step 3: Cross multiply
    78.96x = 118.26 × 78.42
  4. Step 4: Simplify right side
    78.96x = 9,273.95
  5. Step 5: Solve for x
    x = 9,273.95/78.96
  6. Step 6: Final answer
    x = 117.45

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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.