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Finding the Fourth Proportional to 210.29, 290.28 and 121.81

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Solution

The fourth proportional to 210.29, 290.28 and 121.81 is: 168.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    210.29 : 290.28 = 121.81 : x
  2. Step 2: Convert to fraction form
    210.29/290.28 = 121.81/x
  3. Step 3: Cross multiply
    210.29x = 290.28 × 121.81
  4. Step 4: Simplify right side
    210.29x = 35,358.40
  5. Step 5: Solve for x
    x = 35,358.40/210.29
  6. Step 6: Final answer
    x = 168.14

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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.