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Finding the Fourth Proportional to 98.51, 135.90 and 61.65

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Solution

The fourth proportional to 98.51, 135.90 and 61.65 is: 85.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    98.51 : 135.90 = 61.65 : x
  2. Step 2: Convert to fraction form
    98.51/135.90 = 61.65/x
  3. Step 3: Cross multiply
    98.51x = 135.90 × 61.65
  4. Step 4: Simplify right side
    98.51x = 8,378.24
  5. Step 5: Solve for x
    x = 8,378.24/98.51
  6. Step 6: Final answer
    x = 85.05

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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.