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Finding the Fourth Proportional to 66.45, 99.51 and 39.31

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Solution

The fourth proportional to 66.45, 99.51 and 39.31 is: 58.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    66.45 : 99.51 = 39.31 : x
  2. Step 2: Convert to fraction form
    66.45/99.51 = 39.31/x
  3. Step 3: Cross multiply
    66.45x = 99.51 × 39.31
  4. Step 4: Simplify right side
    66.45x = 3,911.74
  5. Step 5: Solve for x
    x = 3,911.74/66.45
  6. Step 6: Final answer
    x = 58.87

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.