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Finding the Fourth Proportional to 70.65, 105.99 and 57.15

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Solution

The fourth proportional to 70.65, 105.99 and 57.15 is: 85.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    70.65 : 105.99 = 57.15 : x
  2. Step 2: Convert to fraction form
    70.65/105.99 = 57.15/x
  3. Step 3: Cross multiply
    70.65x = 105.99 × 57.15
  4. Step 4: Simplify right side
    70.65x = 6,057.33
  5. Step 5: Solve for x
    x = 6,057.33/70.65
  6. Step 6: Final answer
    x = 85.74

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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.