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Finding the Fourth Proportional to 85.50, 127.80 and 70.20

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Solution

The fourth proportional to 85.50, 127.80 and 70.20 is: 104.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    85.50 : 127.80 = 70.20 : x
  2. Step 2: Convert to fraction form
    85.50/127.80 = 70.20/x
  3. Step 3: Cross multiply
    85.50x = 127.80 × 70.20
  4. Step 4: Simplify right side
    85.50x = 8,971.56
  5. Step 5: Solve for x
    x = 8,971.56/85.50
  6. Step 6: Final answer
    x = 104.93

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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.