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Finding the Fourth Proportional to 78.99, 118.91 and 71.55

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Solution

The fourth proportional to 78.99, 118.91 and 71.55 is: 107.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    78.99 : 118.91 = 71.55 : x
  2. Step 2: Convert to fraction form
    78.99/118.91 = 71.55/x
  3. Step 3: Cross multiply
    78.99x = 118.91 × 71.55
  4. Step 4: Simplify right side
    78.99x = 8,507.65
  5. Step 5: Solve for x
    x = 8,507.65/78.99
  6. Step 6: Final answer
    x = 107.71

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These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.