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Finding the Fourth Proportional to 72.81, 100.29 and 68.40

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Solution

The fourth proportional to 72.81, 100.29 and 68.40 is: 94.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    72.81 : 100.29 = 68.40 : x
  2. Step 2: Convert to fraction form
    72.81/100.29 = 68.40/x
  3. Step 3: Cross multiply
    72.81x = 100.29 × 68.40
  4. Step 4: Simplify right side
    72.81x = 6,859.84
  5. Step 5: Solve for x
    x = 6,859.84/72.81
  6. Step 6: Final answer
    x = 94.22

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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.