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Finding the Fourth Proportional to 210.72, 290.72 and 127.80

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Solution

The fourth proportional to 210.72, 290.72 and 127.80 is: 176.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    210.72 : 290.72 = 127.80 : x
  2. Step 2: Convert to fraction form
    210.72/290.72 = 127.80/x
  3. Step 3: Cross multiply
    210.72x = 290.72 × 127.80
  4. Step 4: Simplify right side
    210.72x = 37,153.38
  5. Step 5: Solve for x
    x = 37,153.38/210.72
  6. Step 6: Final answer
    x = 176.32

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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.