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Finding the Fourth Proportional to 84.99, 127.55 and 78.05

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Solution

The fourth proportional to 84.99, 127.55 and 78.05 is: 117.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    84.99 : 127.55 = 78.05 : x
  2. Step 2: Convert to fraction form
    84.99/127.55 = 78.05/x
  3. Step 3: Cross multiply
    84.99x = 127.55 × 78.05
  4. Step 4: Simplify right side
    84.99x = 9,954.25
  5. Step 5: Solve for x
    x = 9,954.25/84.99
  6. Step 6: Final answer
    x = 117.12

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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.