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Finding the Fourth Proportional to 76.96, 106.08 and 65.28

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Solution

The fourth proportional to 76.96, 106.08 and 65.28 is: 89.98

Step by Step Solution

  1. Step 1: Write the proportion equation
    76.96 : 106.08 = 65.28 : x
  2. Step 2: Convert to fraction form
    76.96/106.08 = 65.28/x
  3. Step 3: Cross multiply
    76.96x = 106.08 × 65.28
  4. Step 4: Simplify right side
    76.96x = 6,924.90
  5. Step 5: Solve for x
    x = 6,924.90/76.96
  6. Step 6: Final answer
    x = 89.98

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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.