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Finding the Fourth Proportional to 27.69, 38.12 and 21.21

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Solution

The fourth proportional to 27.69, 38.12 and 21.21 is: 29.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    27.69 : 38.12 = 21.21 : x
  2. Step 2: Convert to fraction form
    27.69/38.12 = 21.21/x
  3. Step 3: Cross multiply
    27.69x = 38.12 × 21.21
  4. Step 4: Simplify right side
    27.69x = 808.53
  5. Step 5: Solve for x
    x = 808.53/27.69
  6. Step 6: Final answer
    x = 29.20

Related Problems

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Double scale
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1.5x scale

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.