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Finding the Fourth Proportional to 98.90, 136.61 and 98.21

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Solution

The fourth proportional to 98.90, 136.61 and 98.21 is: 135.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    98.90 : 136.61 = 98.21 : x
  2. Step 2: Convert to fraction form
    98.90/136.61 = 98.21/x
  3. Step 3: Cross multiply
    98.90x = 136.61 × 98.21
  4. Step 4: Simplify right side
    98.90x = 13,417.06
  5. Step 5: Solve for x
    x = 13,417.06/98.90
  6. Step 6: Final answer
    x = 135.67

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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.