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Finding the Fourth Proportional to 72.09, 99.61 and 64.33

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Solution

The fourth proportional to 72.09, 99.61 and 64.33 is: 88.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    72.09 : 99.61 = 64.33 : x
  2. Step 2: Convert to fraction form
    72.09/99.61 = 64.33/x
  3. Step 3: Cross multiply
    72.09x = 99.61 × 64.33
  4. Step 4: Simplify right side
    72.09x = 6,407.50
  5. Step 5: Solve for x
    x = 6,407.50/72.09
  6. Step 6: Final answer
    x = 88.88

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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.