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Finding the Fourth Proportional to 210.17, 314.91 and 128.81

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Solution

The fourth proportional to 210.17, 314.91 and 128.81 is: 193.00

Step by Step Solution

  1. Step 1: Write the proportion equation
    210.17 : 314.91 = 128.81 : x
  2. Step 2: Convert to fraction form
    210.17/314.91 = 128.81/x
  3. Step 3: Cross multiply
    210.17x = 314.91 × 128.81
  4. Step 4: Simplify right side
    210.17x = 40,561.98
  5. Step 5: Solve for x
    x = 40,561.98/210.17
  6. Step 6: Final answer
    x = 193.00

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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.