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Finding the Fourth Proportional to 78.08, 107.60 and 71.88

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Solution

The fourth proportional to 78.08, 107.60 and 71.88 is: 99.06

Step by Step Solution

  1. Step 1: Write the proportion equation
    78.08 : 107.60 = 71.88 : x
  2. Step 2: Convert to fraction form
    78.08/107.60 = 71.88/x
  3. Step 3: Cross multiply
    78.08x = 107.60 × 71.88
  4. Step 4: Simplify right side
    78.08x = 7,734.29
  5. Step 5: Solve for x
    x = 7,734.29/78.08
  6. Step 6: Final answer
    x = 99.06

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.