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Finding the Fourth Proportional to 253.40, 379.79 and 90.89

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Solution

The fourth proportional to 253.40, 379.79 and 90.89 is: 136.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    253.40 : 379.79 = 90.89 : x
  2. Step 2: Convert to fraction form
    253.40/379.79 = 90.89/x
  3. Step 3: Cross multiply
    253.40x = 379.79 × 90.89
  4. Step 4: Simplify right side
    253.40x = 34,518.52
  5. Step 5: Solve for x
    x = 34,518.52/253.40
  6. Step 6: Final answer
    x = 136.22

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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.