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Finding the Fourth Proportional to 65.76, 90.72 and 57.96

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Solution

The fourth proportional to 65.76, 90.72 and 57.96 is: 79.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    65.76 : 90.72 = 57.96 : x
  2. Step 2: Convert to fraction form
    65.76/90.72 = 57.96/x
  3. Step 3: Cross multiply
    65.76x = 90.72 × 57.96
  4. Step 4: Simplify right side
    65.76x = 5,258.13
  5. Step 5: Solve for x
    x = 5,258.13/65.76
  6. Step 6: Final answer
    x = 79.96

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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.