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Finding the Fourth Proportional to 15.51, 21.25 and 15.25

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Solution

The fourth proportional to 15.51, 21.25 and 15.25 is: 20.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    15.51 : 21.25 = 15.25 : x
  2. Step 2: Convert to fraction form
    15.51/21.25 = 15.25/x
  3. Step 3: Cross multiply
    15.51x = 21.25 × 15.25
  4. Step 4: Simplify right side
    15.51x = 324.06
  5. Step 5: Solve for x
    x = 324.06/15.51
  6. Step 6: Final answer
    x = 20.89

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.