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Finding the Fourth Proportional to 78.26, 117.48 and 77.88

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Solution

The fourth proportional to 78.26, 117.48 and 77.88 is: 116.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    78.26 : 117.48 = 77.88 : x
  2. Step 2: Convert to fraction form
    78.26/117.48 = 77.88/x
  3. Step 3: Cross multiply
    78.26x = 117.48 × 77.88
  4. Step 4: Simplify right side
    78.26x = 9,149.34
  5. Step 5: Solve for x
    x = 9,149.34/78.26
  6. Step 6: Final answer
    x = 116.91

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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.