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Finding the Fourth Proportional to 78.91, 108.75 and 70.18

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Solution

The fourth proportional to 78.91, 108.75 and 70.18 is: 96.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    78.91 : 108.75 = 70.18 : x
  2. Step 2: Convert to fraction form
    78.91/108.75 = 70.18/x
  3. Step 3: Cross multiply
    78.91x = 108.75 × 70.18
  4. Step 4: Simplify right side
    78.91x = 7,632.08
  5. Step 5: Solve for x
    x = 7,632.08/78.91
  6. Step 6: Final answer
    x = 96.72

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.