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Finding the Fourth Proportional to 210.90, 290.91 and 123.57

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Solution

The fourth proportional to 210.90, 290.91 and 123.57 is: 170.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    210.90 : 290.91 = 123.57 : x
  2. Step 2: Convert to fraction form
    210.90/290.91 = 123.57/x
  3. Step 3: Cross multiply
    210.90x = 290.91 × 123.57
  4. Step 4: Simplify right side
    210.90x = 35,947.75
  5. Step 5: Solve for x
    x = 35,947.75/210.90
  6. Step 6: Final answer
    x = 170.45

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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.