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Finding the Fourth Proportional to 65.89, 90.78 and 54.94

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Solution

The fourth proportional to 65.89, 90.78 and 54.94 is: 75.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    65.89 : 90.78 = 54.94 : x
  2. Step 2: Convert to fraction form
    65.89/90.78 = 54.94/x
  3. Step 3: Cross multiply
    65.89x = 90.78 × 54.94
  4. Step 4: Simplify right side
    65.89x = 4,987.45
  5. Step 5: Solve for x
    x = 4,987.45/65.89
  6. Step 6: Final answer
    x = 75.69

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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.