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Finding the Fourth Proportional to 78.93, 118.35 and 72.90

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Solution

The fourth proportional to 78.93, 118.35 and 72.90 is: 109.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    78.93 : 118.35 = 72.90 : x
  2. Step 2: Convert to fraction form
    78.93/118.35 = 72.90/x
  3. Step 3: Cross multiply
    78.93x = 118.35 × 72.90
  4. Step 4: Simplify right side
    78.93x = 8,627.72
  5. Step 5: Solve for x
    x = 8,627.72/78.93
  6. Step 6: Final answer
    x = 109.31

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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.