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Finding the Fourth Proportional to 158.10, 217.98 and 99.90

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Solution

The fourth proportional to 158.10, 217.98 and 99.90 is: 137.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    158.10 : 217.98 = 99.90 : x
  2. Step 2: Convert to fraction form
    158.10/217.98 = 99.90/x
  3. Step 3: Cross multiply
    158.10x = 217.98 × 99.90
  4. Step 4: Simplify right side
    158.10x = 21,776.20
  5. Step 5: Solve for x
    x = 21,776.20/158.10
  6. Step 6: Final answer
    x = 137.74

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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.