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Finding the Fourth Proportional to 15.63, 21.58 and 9.81

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Solution

The fourth proportional to 15.63, 21.58 and 9.81 is: 13.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    15.63 : 21.58 = 9.81 : x
  2. Step 2: Convert to fraction form
    15.63/21.58 = 9.81/x
  3. Step 3: Cross multiply
    15.63x = 21.58 × 9.81
  4. Step 4: Simplify right side
    15.63x = 211.83
  5. Step 5: Solve for x
    x = 211.83/15.63
  6. Step 6: Final answer
    x = 13.55

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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.