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Finding the Fourth Proportional to 15.21, 21 and 12.48

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Solution

The fourth proportional to 15.21, 21 and 12.48 is: 17.24

Step by Step Solution

  1. Step 1: Write the proportion equation
    15.21 : 21 = 12.48 : x
  2. Step 2: Convert to fraction form
    15.21/21 = 12.48/x
  3. Step 3: Cross multiply
    15.21x = 21 × 12.48
  4. Step 4: Simplify right side
    15.21x = 262.13
  5. Step 5: Solve for x
    x = 262.13/15.21
  6. Step 6: Final answer
    x = 17.24

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1.5x scale

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.