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Finding the Fourth Proportional to 15.51, 21.38 and 10.65

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Solution

The fourth proportional to 15.51, 21.38 and 10.65 is: 14.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    15.51 : 21.38 = 10.65 : x
  2. Step 2: Convert to fraction form
    15.51/21.38 = 10.65/x
  3. Step 3: Cross multiply
    15.51x = 21.38 × 10.65
  4. Step 4: Simplify right side
    15.51x = 227.64
  5. Step 5: Solve for x
    x = 227.64/15.51
  6. Step 6: Final answer
    x = 14.68

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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.