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Finding the Fourth Proportional to 72.08, 99.45 and 48.78

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Solution

The fourth proportional to 72.08, 99.45 and 48.78 is: 67.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    72.08 : 99.45 = 48.78 : x
  2. Step 2: Convert to fraction form
    72.08/99.45 = 48.78/x
  3. Step 3: Cross multiply
    72.08x = 99.45 × 48.78
  4. Step 4: Simplify right side
    72.08x = 4,851.17
  5. Step 5: Solve for x
    x = 4,851.17/72.08
  6. Step 6: Final answer
    x = 67.31

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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.