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Finding the Fourth Proportional to 79.64, 109.86 and 53.78

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Solution

The fourth proportional to 79.64, 109.86 and 53.78 is: 74.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    79.64 : 109.86 = 53.78 : x
  2. Step 2: Convert to fraction form
    79.64/109.86 = 53.78/x
  3. Step 3: Cross multiply
    79.64x = 109.86 × 53.78
  4. Step 4: Simplify right side
    79.64x = 5,908.27
  5. Step 5: Solve for x
    x = 5,908.27/79.64
  6. Step 6: Final answer
    x = 74.19

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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.