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Finding the Fourth Proportional to 251.43, 377.21 and 78.15

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Solution

The fourth proportional to 251.43, 377.21 and 78.15 is: 117.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    251.43 : 377.21 = 78.15 : x
  2. Step 2: Convert to fraction form
    251.43/377.21 = 78.15/x
  3. Step 3: Cross multiply
    251.43x = 377.21 × 78.15
  4. Step 4: Simplify right side
    251.43x = 29,478.96
  5. Step 5: Solve for x
    x = 29,478.96/251.43
  6. Step 6: Final answer
    x = 117.25

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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.