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Finding the Fourth Proportional to 66.17, 91.91 and 65.12

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Solution

The fourth proportional to 66.17, 91.91 and 65.12 is: 90.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    66.17 : 91.91 = 65.12 : x
  2. Step 2: Convert to fraction form
    66.17/91.91 = 65.12/x
  3. Step 3: Cross multiply
    66.17x = 91.91 × 65.12
  4. Step 4: Simplify right side
    66.17x = 5,984.39
  5. Step 5: Solve for x
    x = 5,984.39/66.17
  6. Step 6: Final answer
    x = 90.45

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Why These Related Problems?

These problems maintain the same ratio (1.39) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.