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Finding the Fourth Proportional to 79.50, 109.72 and 55.00

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Solution

The fourth proportional to 79.50, 109.72 and 55.00 is: 75.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    79.50 : 109.72 = 55.00 : x
  2. Step 2: Convert to fraction form
    79.50/109.72 = 55.00/x
  3. Step 3: Cross multiply
    79.50x = 109.72 × 55.00
  4. Step 4: Simplify right side
    79.50x = 6,034.81
  5. Step 5: Solve for x
    x = 6,034.81/79.50
  6. Step 6: Final answer
    x = 75.91

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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.