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Finding the Fourth Proportional to 91.21, 136.30 and 89.16

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Solution

The fourth proportional to 91.21, 136.30 and 89.16 is: 133.24

Step by Step Solution

  1. Step 1: Write the proportion equation
    91.21 : 136.30 = 89.16 : x
  2. Step 2: Convert to fraction form
    91.21/136.30 = 89.16/x
  3. Step 3: Cross multiply
    91.21x = 136.30 × 89.16
  4. Step 4: Simplify right side
    91.21x = 12,152.51
  5. Step 5: Solve for x
    x = 12,152.51/91.21
  6. Step 6: Final answer
    x = 133.24

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.