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Finding the Fourth Proportional to 57.78, 79.75 and 47.39

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Solution

The fourth proportional to 57.78, 79.75 and 47.39 is: 65.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    57.78 : 79.75 = 47.39 : x
  2. Step 2: Convert to fraction form
    57.78/79.75 = 47.39/x
  3. Step 3: Cross multiply
    57.78x = 79.75 × 47.39
  4. Step 4: Simplify right side
    57.78x = 3,779.49
  5. Step 5: Solve for x
    x = 3,779.49/57.78
  6. Step 6: Final answer
    x = 65.41

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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.