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Finding the Fourth Proportional to 21.22, 32 and 18.71

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Solution

The fourth proportional to 21.22, 32 and 18.71 is: 28.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    21.22 : 32 = 18.71 : x
  2. Step 2: Convert to fraction form
    21.22/32 = 18.71/x
  3. Step 3: Cross multiply
    21.22x = 32 × 18.71
  4. Step 4: Simplify right side
    21.22x = 598.72
  5. Step 5: Solve for x
    x = 598.72/21.22
  6. Step 6: Final answer
    x = 28.21

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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.