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Finding the Fourth Proportional to 22.80, 31.44 and 21.28

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Solution

The fourth proportional to 22.80, 31.44 and 21.28 is: 29.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    22.80 : 31.44 = 21.28 : x
  2. Step 2: Convert to fraction form
    22.80/31.44 = 21.28/x
  3. Step 3: Cross multiply
    22.80x = 31.44 × 21.28
  4. Step 4: Simplify right side
    22.80x = 669.04
  5. Step 5: Solve for x
    x = 669.04/22.80
  6. Step 6: Final answer
    x = 29.34

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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.