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Finding the Fourth Proportional to 140.66, 210.98 and 86.45

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Solution

The fourth proportional to 140.66, 210.98 and 86.45 is: 129.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    140.66 : 210.98 = 86.45 : x
  2. Step 2: Convert to fraction form
    140.66/210.98 = 86.45/x
  3. Step 3: Cross multiply
    140.66x = 210.98 × 86.45
  4. Step 4: Simplify right side
    140.66x = 18,239.22
  5. Step 5: Solve for x
    x = 18,239.22/140.66
  6. Step 6: Final answer
    x = 129.67

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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.