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Finding the Fourth Proportional to 66.31, 91.06 and 57.10

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Solution

The fourth proportional to 66.31, 91.06 and 57.10 is: 78.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    66.31 : 91.06 = 57.10 : x
  2. Step 2: Convert to fraction form
    66.31/91.06 = 57.10/x
  3. Step 3: Cross multiply
    66.31x = 91.06 × 57.10
  4. Step 4: Simplify right side
    66.31x = 5,199.53
  5. Step 5: Solve for x
    x = 5,199.53/66.31
  6. Step 6: Final answer
    x = 78.41

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.