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Finding the Fourth Proportional to 158.21, 218.31 and 99.98

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Solution

The fourth proportional to 158.21, 218.31 and 99.98 is: 137.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    158.21 : 218.31 = 99.98 : x
  2. Step 2: Convert to fraction form
    158.21/218.31 = 99.98/x
  3. Step 3: Cross multiply
    158.21x = 218.31 × 99.98
  4. Step 4: Simplify right side
    158.21x = 21,826.63
  5. Step 5: Solve for x
    x = 21,826.63/158.21
  6. Step 6: Final answer
    x = 137.96

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.