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Finding the Fourth Proportional to 210.98, 316.38 and 129.80

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Solution

The fourth proportional to 210.98, 316.38 and 129.80 is: 194.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    210.98 : 316.38 = 129.80 : x
  2. Step 2: Convert to fraction form
    210.98/316.38 = 129.80/x
  3. Step 3: Cross multiply
    210.98x = 316.38 × 129.80
  4. Step 4: Simplify right side
    210.98x = 41,066.12
  5. Step 5: Solve for x
    x = 41,066.12/210.98
  6. Step 6: Final answer
    x = 194.64

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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.