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Finding the Fourth Proportional to 94.26, 129.78 and 76.80

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Solution

The fourth proportional to 94.26, 129.78 and 76.80 is: 105.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    94.26 : 129.78 = 76.80 : x
  2. Step 2: Convert to fraction form
    94.26/129.78 = 76.80/x
  3. Step 3: Cross multiply
    94.26x = 129.78 × 76.80
  4. Step 4: Simplify right side
    94.26x = 9,967.10
  5. Step 5: Solve for x
    x = 9,967.10/94.26
  6. Step 6: Final answer
    x = 105.74

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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.