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Finding the Fourth Proportional to 66.41, 99.78 and 57.90

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Solution

The fourth proportional to 66.41, 99.78 and 57.90 is: 86.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    66.41 : 99.78 = 57.90 : x
  2. Step 2: Convert to fraction form
    66.41/99.78 = 57.90/x
  3. Step 3: Cross multiply
    66.41x = 99.78 × 57.90
  4. Step 4: Simplify right side
    66.41x = 5,777.26
  5. Step 5: Solve for x
    x = 5,777.26/66.41
  6. Step 6: Final answer
    x = 86.99

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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.