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Finding the Fourth Proportional to 76.32, 105.08 and 65.22

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Solution

The fourth proportional to 76.32, 105.08 and 65.22 is: 89.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    76.32 : 105.08 = 65.22 : x
  2. Step 2: Convert to fraction form
    76.32/105.08 = 65.22/x
  3. Step 3: Cross multiply
    76.32x = 105.08 × 65.22
  4. Step 4: Simplify right side
    76.32x = 6,853.32
  5. Step 5: Solve for x
    x = 6,853.32/76.32
  6. Step 6: Final answer
    x = 89.80

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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.