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Finding the Fourth Proportional to 85.40, 127.99 and 76.28

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Solution

The fourth proportional to 85.40, 127.99 and 76.28 is: 114.33

Step by Step Solution

  1. Step 1: Write the proportion equation
    85.40 : 127.99 = 76.28 : x
  2. Step 2: Convert to fraction form
    85.40/127.99 = 76.28/x
  3. Step 3: Cross multiply
    85.40x = 127.99 × 76.28
  4. Step 4: Simplify right side
    85.40x = 9,763.21
  5. Step 5: Solve for x
    x = 9,763.21/85.40
  6. Step 6: Final answer
    x = 114.33

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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.