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Finding the Fourth Proportional to 92.90, 128.09 and 79.94

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Solution

The fourth proportional to 92.90, 128.09 and 79.94 is: 110.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    92.90 : 128.09 = 79.94 : x
  2. Step 2: Convert to fraction form
    92.90/128.09 = 79.94/x
  3. Step 3: Cross multiply
    92.90x = 128.09 × 79.94
  4. Step 4: Simplify right side
    92.90x = 10,239.51
  5. Step 5: Solve for x
    x = 10,239.51/92.90
  6. Step 6: Final answer
    x = 110.22

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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.