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Finding the Fourth Proportional to 128.23, 176.98 and 72.22

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Solution

The fourth proportional to 128.23, 176.98 and 72.22 is: 99.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    128.23 : 176.98 = 72.22 : x
  2. Step 2: Convert to fraction form
    128.23/176.98 = 72.22/x
  3. Step 3: Cross multiply
    128.23x = 176.98 × 72.22
  4. Step 4: Simplify right side
    128.23x = 12,781.81
  5. Step 5: Solve for x
    x = 12,781.81/128.23
  6. Step 6: Final answer
    x = 99.68

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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.