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Finding the Fourth Proportional to 76.80, 106.72 and 76.50

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Solution

The fourth proportional to 76.80, 106.72 and 76.50 is: 106.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    76.80 : 106.72 = 76.50 : x
  2. Step 2: Convert to fraction form
    76.80/106.72 = 76.50/x
  3. Step 3: Cross multiply
    76.80x = 106.72 × 76.50
  4. Step 4: Simplify right side
    76.80x = 8,164.08
  5. Step 5: Solve for x
    x = 8,164.08/76.80
  6. Step 6: Final answer
    x = 106.30

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Why These Related Problems?

These problems maintain the same ratio (1.39) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.