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Finding the Fourth Proportional to 76.70, 115.04 and 72.75

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Solution

The fourth proportional to 76.70, 115.04 and 72.75 is: 109.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    76.70 : 115.04 = 72.75 : x
  2. Step 2: Convert to fraction form
    76.70/115.04 = 72.75/x
  3. Step 3: Cross multiply
    76.70x = 115.04 × 72.75
  4. Step 4: Simplify right side
    76.70x = 8,368.80
  5. Step 5: Solve for x
    x = 8,368.80/76.70
  6. Step 6: Final answer
    x = 109.12

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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.