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Finding the Fourth Proportional to 65.80, 91.06 and 64.20

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Solution

The fourth proportional to 65.80, 91.06 and 64.20 is: 88.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    65.80 : 91.06 = 64.20 : x
  2. Step 2: Convert to fraction form
    65.80/91.06 = 64.20/x
  3. Step 3: Cross multiply
    65.80x = 91.06 × 64.20
  4. Step 4: Simplify right side
    65.80x = 5,846.05
  5. Step 5: Solve for x
    x = 5,846.05/65.80
  6. Step 6: Final answer
    x = 88.85

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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.