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Finding the Fourth Proportional to 48.78, 72.86 and 39.66

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Solution

The fourth proportional to 48.78, 72.86 and 39.66 is: 59.23

Step by Step Solution

  1. Step 1: Write the proportion equation
    48.78 : 72.86 = 39.66 : x
  2. Step 2: Convert to fraction form
    48.78/72.86 = 39.66/x
  3. Step 3: Cross multiply
    48.78x = 72.86 × 39.66
  4. Step 4: Simplify right side
    48.78x = 2,889.43
  5. Step 5: Solve for x
    x = 2,889.43/48.78
  6. Step 6: Final answer
    x = 59.23

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.