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Finding the Fourth Proportional to 61.08, 83.79 and 57.40

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Solution

The fourth proportional to 61.08, 83.79 and 57.40 is: 78.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    61.08 : 83.79 = 57.40 : x
  2. Step 2: Convert to fraction form
    61.08/83.79 = 57.40/x
  3. Step 3: Cross multiply
    61.08x = 83.79 × 57.40
  4. Step 4: Simplify right side
    61.08x = 4,809.55
  5. Step 5: Solve for x
    x = 4,809.55/61.08
  6. Step 6: Final answer
    x = 78.74

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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.