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Finding the Fourth Proportional to 253.39, 379.90 and 99.31

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Solution

The fourth proportional to 253.39, 379.90 and 99.31 is: 148.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    253.39 : 379.90 = 99.31 : x
  2. Step 2: Convert to fraction form
    253.39/379.90 = 99.31/x
  3. Step 3: Cross multiply
    253.39x = 379.90 × 99.31
  4. Step 4: Simplify right side
    253.39x = 37,727.87
  5. Step 5: Solve for x
    x = 37,727.87/253.39
  6. Step 6: Final answer
    x = 148.89

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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.