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Finding the Fourth Proportional to 79.71, 109.91 and 70.47

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Solution

The fourth proportional to 79.71, 109.91 and 70.47 is: 97.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    79.71 : 109.91 = 70.47 : x
  2. Step 2: Convert to fraction form
    79.71/109.91 = 70.47/x
  3. Step 3: Cross multiply
    79.71x = 109.91 × 70.47
  4. Step 4: Simplify right side
    79.71x = 7,744.46
  5. Step 5: Solve for x
    x = 7,744.46/79.71
  6. Step 6: Final answer
    x = 97.16

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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.