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Finding the Fourth Proportional to 65.45, 90.30 and 55.79

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Solution

The fourth proportional to 65.45, 90.30 and 55.79 is: 76.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    65.45 : 90.30 = 55.79 : x
  2. Step 2: Convert to fraction form
    65.45/90.30 = 55.79/x
  3. Step 3: Cross multiply
    65.45x = 90.30 × 55.79
  4. Step 4: Simplify right side
    65.45x = 5,037.39
  5. Step 5: Solve for x
    x = 5,037.39/65.45
  6. Step 6: Final answer
    x = 76.97

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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.