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Finding the Fourth Proportional to 20.61, 28.51 and 18.19

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Solution

The fourth proportional to 20.61, 28.51 and 18.19 is: 25.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    20.61 : 28.51 = 18.19 : x
  2. Step 2: Convert to fraction form
    20.61/28.51 = 18.19/x
  3. Step 3: Cross multiply
    20.61x = 28.51 × 18.19
  4. Step 4: Simplify right side
    20.61x = 518.55
  5. Step 5: Solve for x
    x = 518.55/20.61
  6. Step 6: Final answer
    x = 25.16

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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.