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Finding the Fourth Proportional to 66.28, 91.47 and 38.65

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Solution

The fourth proportional to 66.28, 91.47 and 38.65 is: 53.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    66.28 : 91.47 = 38.65 : x
  2. Step 2: Convert to fraction form
    66.28/91.47 = 38.65/x
  3. Step 3: Cross multiply
    66.28x = 91.47 × 38.65
  4. Step 4: Simplify right side
    66.28x = 3,535.09
  5. Step 5: Solve for x
    x = 3,535.09/66.28
  6. Step 6: Final answer
    x = 53.34

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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.