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Finding the Fourth Proportional to 210.81, 290.90 and 123.47

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Solution

The fourth proportional to 210.81, 290.90 and 123.47 is: 170.37

Step by Step Solution

  1. Step 1: Write the proportion equation
    210.81 : 290.90 = 123.47 : x
  2. Step 2: Convert to fraction form
    210.81/290.90 = 123.47/x
  3. Step 3: Cross multiply
    210.81x = 290.90 × 123.47
  4. Step 4: Simplify right side
    210.81x = 35,917.37
  5. Step 5: Solve for x
    x = 35,917.37/210.81
  6. Step 6: Final answer
    x = 170.37

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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.