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Finding the Fourth Proportional to 98.45, 147.41 and 86.15

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Solution

The fourth proportional to 98.45, 147.41 and 86.15 is: 128.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    98.45 : 147.41 = 86.15 : x
  2. Step 2: Convert to fraction form
    98.45/147.41 = 86.15/x
  3. Step 3: Cross multiply
    98.45x = 147.41 × 86.15
  4. Step 4: Simplify right side
    98.45x = 12,698.20
  5. Step 5: Solve for x
    x = 12,698.20/98.45
  6. Step 6: Final answer
    x = 128.99

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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.