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Finding the Fourth Proportional to 20, 27.60 and 15.70

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Solution

The fourth proportional to 20, 27.60 and 15.70 is: 21.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    20 : 27.60 = 15.70 : x
  2. Step 2: Convert to fraction form
    20/27.60 = 15.70/x
  3. Step 3: Cross multiply
    20x = 27.60 × 15.70
  4. Step 4: Simplify right side
    20x = 433.32
  5. Step 5: Solve for x
    x = 433.32/20
  6. Step 6: Final answer
    x = 21.67

Related Problems

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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.