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Finding the Fourth Proportional to 72.25, 99.72 and 64.15

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Solution

The fourth proportional to 72.25, 99.72 and 64.15 is: 88.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    72.25 : 99.72 = 64.15 : x
  2. Step 2: Convert to fraction form
    72.25/99.72 = 64.15/x
  3. Step 3: Cross multiply
    72.25x = 99.72 × 64.15
  4. Step 4: Simplify right side
    72.25x = 6,397.04
  5. Step 5: Solve for x
    x = 6,397.04/72.25
  6. Step 6: Final answer
    x = 88.54

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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.