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Finding the Fourth Proportional to 91.15, 137.25 and 64.28

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Solution

The fourth proportional to 91.15, 137.25 and 64.28 is: 96.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    91.15 : 137.25 = 64.28 : x
  2. Step 2: Convert to fraction form
    91.15/137.25 = 64.28/x
  3. Step 3: Cross multiply
    91.15x = 137.25 × 64.28
  4. Step 4: Simplify right side
    91.15x = 8,822.77
  5. Step 5: Solve for x
    x = 8,822.77/91.15
  6. Step 6: Final answer
    x = 96.80

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.