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Finding the Fourth Proportional to 74.77, 103.19 and 72.79

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Solution

The fourth proportional to 74.77, 103.19 and 72.79 is: 100.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    74.77 : 103.19 = 72.79 : x
  2. Step 2: Convert to fraction form
    74.77/103.19 = 72.79/x
  3. Step 3: Cross multiply
    74.77x = 103.19 × 72.79
  4. Step 4: Simplify right side
    74.77x = 7,510.58
  5. Step 5: Solve for x
    x = 7,510.58/74.77
  6. Step 6: Final answer
    x = 100.45

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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.