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Finding the Fourth Proportional to 66.25, 91.47 and 40.42

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Solution

The fourth proportional to 66.25, 91.47 and 40.42 is: 55.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    66.25 : 91.47 = 40.42 : x
  2. Step 2: Convert to fraction form
    66.25/91.47 = 40.42/x
  3. Step 3: Cross multiply
    66.25x = 91.47 × 40.42
  4. Step 4: Simplify right side
    66.25x = 3,697.22
  5. Step 5: Solve for x
    x = 3,697.22/66.25
  6. Step 6: Final answer
    x = 55.81

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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.