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Finding the Fourth Proportional to 65.96, 90.68 and 56.80

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Solution

The fourth proportional to 65.96, 90.68 and 56.80 is: 78.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    65.96 : 90.68 = 56.80 : x
  2. Step 2: Convert to fraction form
    65.96/90.68 = 56.80/x
  3. Step 3: Cross multiply
    65.96x = 90.68 × 56.80
  4. Step 4: Simplify right side
    65.96x = 5,150.62
  5. Step 5: Solve for x
    x = 5,150.62/65.96
  6. Step 6: Final answer
    x = 78.09

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.