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Finding the Fourth Proportional to 102.39, 153.59 and 90.65

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Solution

The fourth proportional to 102.39, 153.59 and 90.65 is: 135.98

Step by Step Solution

  1. Step 1: Write the proportion equation
    102.39 : 153.59 = 90.65 : x
  2. Step 2: Convert to fraction form
    102.39/153.59 = 90.65/x
  3. Step 3: Cross multiply
    102.39x = 153.59 × 90.65
  4. Step 4: Simplify right side
    102.39x = 13,922.93
  5. Step 5: Solve for x
    x = 13,922.93/102.39
  6. Step 6: Final answer
    x = 135.98

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.