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Finding the Fourth Proportional to 78.71, 118.10 and 38.15

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Solution

The fourth proportional to 78.71, 118.10 and 38.15 is: 57.23

Step by Step Solution

  1. Step 1: Write the proportion equation
    78.71 : 118.10 = 38.15 : x
  2. Step 2: Convert to fraction form
    78.71/118.10 = 38.15/x
  3. Step 3: Cross multiply
    78.71x = 118.10 × 38.15
  4. Step 4: Simplify right side
    78.71x = 4,505.02
  5. Step 5: Solve for x
    x = 4,505.02/78.71
  6. Step 6: Final answer
    x = 57.23

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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.