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Finding the Fourth Proportional to 85.43, 128.18 and 27.68

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Solution

The fourth proportional to 85.43, 128.18 and 27.68 is: 41.52

Step by Step Solution

  1. Step 1: Write the proportion equation
    85.43 : 128.18 = 27.68 : x
  2. Step 2: Convert to fraction form
    85.43/128.18 = 27.68/x
  3. Step 3: Cross multiply
    85.43x = 128.18 × 27.68
  4. Step 4: Simplify right side
    85.43x = 3,547.45
  5. Step 5: Solve for x
    x = 3,547.45/85.43
  6. Step 6: Final answer
    x = 41.52

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.