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Finding the Fourth Proportional to 21.47, 32.00 and 20.72

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Solution

The fourth proportional to 21.47, 32.00 and 20.72 is: 30.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    21.47 : 32.00 = 20.72 : x
  2. Step 2: Convert to fraction form
    21.47/32.00 = 20.72/x
  3. Step 3: Cross multiply
    21.47x = 32.00 × 20.72
  4. Step 4: Simplify right side
    21.47x = 663.02
  5. Step 5: Solve for x
    x = 663.02/21.47
  6. Step 6: Final answer
    x = 30.89

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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.