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Finding the Fourth Proportional to 30.76, 42.38 and 28.14

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Solution

The fourth proportional to 30.76, 42.38 and 28.14 is: 38.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    30.76 : 42.38 = 28.14 : x
  2. Step 2: Convert to fraction form
    30.76/42.38 = 28.14/x
  3. Step 3: Cross multiply
    30.76x = 42.38 × 28.14
  4. Step 4: Simplify right side
    30.76x = 1,192.57
  5. Step 5: Solve for x
    x = 1,192.57/30.76
  6. Step 6: Final answer
    x = 38.77

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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.