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Finding the Fourth Proportional to 210.87, 291.05 and 123.55

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Solution

The fourth proportional to 210.87, 291.05 and 123.55 is: 170.53

Step by Step Solution

  1. Step 1: Write the proportion equation
    210.87 : 291.05 = 123.55 : x
  2. Step 2: Convert to fraction form
    210.87/291.05 = 123.55/x
  3. Step 3: Cross multiply
    210.87x = 291.05 × 123.55
  4. Step 4: Simplify right side
    210.87x = 35,959.23
  5. Step 5: Solve for x
    x = 35,959.23/210.87
  6. Step 6: Final answer
    x = 170.53

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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.