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Finding the Fourth Proportional to 65.95, 90.89 and 57.31

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Solution

The fourth proportional to 65.95, 90.89 and 57.31 is: 78.98

Step by Step Solution

  1. Step 1: Write the proportion equation
    65.95 : 90.89 = 57.31 : x
  2. Step 2: Convert to fraction form
    65.95/90.89 = 57.31/x
  3. Step 3: Cross multiply
    65.95x = 90.89 × 57.31
  4. Step 4: Simplify right side
    65.95x = 5,208.62
  5. Step 5: Solve for x
    x = 5,208.62/65.95
  6. Step 6: Final answer
    x = 78.98

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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.