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Finding the Fourth Proportional to 79.45, 109.62 and 71.28

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Solution

The fourth proportional to 79.45, 109.62 and 71.28 is: 98.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    79.45 : 109.62 = 71.28 : x
  2. Step 2: Convert to fraction form
    79.45/109.62 = 71.28/x
  3. Step 3: Cross multiply
    79.45x = 109.62 × 71.28
  4. Step 4: Simplify right side
    79.45x = 7,813.71
  5. Step 5: Solve for x
    x = 7,813.71/79.45
  6. Step 6: Final answer
    x = 98.35

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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.