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Finding the Fourth Proportional to 79.40, 118.55 and 61.38

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Solution

The fourth proportional to 79.40, 118.55 and 61.38 is: 91.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    79.40 : 118.55 = 61.38 : x
  2. Step 2: Convert to fraction form
    79.40/118.55 = 61.38/x
  3. Step 3: Cross multiply
    79.40x = 118.55 × 61.38
  4. Step 4: Simplify right side
    79.40x = 7,276.29
  5. Step 5: Solve for x
    x = 7,276.29/79.40
  6. Step 6: Final answer
    x = 91.65

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.