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Finding the Fourth Proportional to 70.65, 105.75 and 55.15

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Solution

The fourth proportional to 70.65, 105.75 and 55.15 is: 82.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    70.65 : 105.75 = 55.15 : x
  2. Step 2: Convert to fraction form
    70.65/105.75 = 55.15/x
  3. Step 3: Cross multiply
    70.65x = 105.75 × 55.15
  4. Step 4: Simplify right side
    70.65x = 5,831.85
  5. Step 5: Solve for x
    x = 5,831.85/70.65
  6. Step 6: Final answer
    x = 82.55

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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.