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Finding the Fourth Proportional to 76.89, 106.05 and 61.35

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Solution

The fourth proportional to 76.89, 106.05 and 61.35 is: 84.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    76.89 : 106.05 = 61.35 : x
  2. Step 2: Convert to fraction form
    76.89/106.05 = 61.35/x
  3. Step 3: Cross multiply
    76.89x = 106.05 × 61.35
  4. Step 4: Simplify right side
    76.89x = 6,506.17
  5. Step 5: Solve for x
    x = 6,506.17/76.89
  6. Step 6: Final answer
    x = 84.62

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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.