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Finding the Fourth Proportional to 20.76, 28.65 and 12.57

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Solution

The fourth proportional to 20.76, 28.65 and 12.57 is: 17.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    20.76 : 28.65 = 12.57 : x
  2. Step 2: Convert to fraction form
    20.76/28.65 = 12.57/x
  3. Step 3: Cross multiply
    20.76x = 28.65 × 12.57
  4. Step 4: Simplify right side
    20.76x = 360.07
  5. Step 5: Solve for x
    x = 360.07/20.76
  6. Step 6: Final answer
    x = 17.34

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Find fourth proportional to 10.38, 14.32 and 6.29
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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.