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Finding the Fourth Proportional to 27.89, 38.50 and 21.00

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Solution

The fourth proportional to 27.89, 38.50 and 21.00 is: 28.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    27.89 : 38.50 = 21.00 : x
  2. Step 2: Convert to fraction form
    27.89/38.50 = 21.00/x
  3. Step 3: Cross multiply
    27.89x = 38.50 × 21.00
  4. Step 4: Simplify right side
    27.89x = 808.38
  5. Step 5: Solve for x
    x = 808.38/27.89
  6. Step 6: Final answer
    x = 28.99

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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.