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Finding the Fourth Proportional to 21.40, 29.50 and 15.25

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Solution

The fourth proportional to 21.40, 29.50 and 15.25 is: 21.02

Step by Step Solution

  1. Step 1: Write the proportion equation
    21.40 : 29.50 = 15.25 : x
  2. Step 2: Convert to fraction form
    21.40/29.50 = 15.25/x
  3. Step 3: Cross multiply
    21.40x = 29.50 × 15.25
  4. Step 4: Simplify right side
    21.40x = 449.65
  5. Step 5: Solve for x
    x = 449.65/21.40
  6. Step 6: Final answer
    x = 21.02

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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.