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Finding the Fourth Proportional to 57.16, 78.94 and 39.68

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Solution

The fourth proportional to 57.16, 78.94 and 39.68 is: 54.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    57.16 : 78.94 = 39.68 : x
  2. Step 2: Convert to fraction form
    57.16/78.94 = 39.68/x
  3. Step 3: Cross multiply
    57.16x = 78.94 × 39.68
  4. Step 4: Simplify right side
    57.16x = 3,132.34
  5. Step 5: Solve for x
    x = 3,132.34/57.16
  6. Step 6: Final answer
    x = 54.80

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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.