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Finding the Fourth Proportional to 79.45, 109.76 and 72.50

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Solution

The fourth proportional to 79.45, 109.76 and 72.50 is: 100.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    79.45 : 109.76 = 72.50 : x
  2. Step 2: Convert to fraction form
    79.45/109.76 = 72.50/x
  3. Step 3: Cross multiply
    79.45x = 109.76 × 72.50
  4. Step 4: Simplify right side
    79.45x = 7,956.69
  5. Step 5: Solve for x
    x = 7,956.69/79.45
  6. Step 6: Final answer
    x = 100.15

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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.