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Finding the Fourth Proportional to 5.21, 7.21 and 5.00

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Solution

The fourth proportional to 5.21, 7.21 and 5.00 is: 6.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    5.21 : 7.21 = 5.00 : x
  2. Step 2: Convert to fraction form
    5.21/7.21 = 5.00/x
  3. Step 3: Cross multiply
    5.21x = 7.21 × 5.00
  4. Step 4: Simplify right side
    5.21x = 36.03
  5. Step 5: Solve for x
    x = 36.03/5.21
  6. Step 6: Final answer
    x = 6.92

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Why These Related Problems?

These problems maintain the same ratio (1.39) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.