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Finding the Fourth Proportional to 30.47, 42 and 18.18

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Solution

The fourth proportional to 30.47, 42 and 18.18 is: 25.06

Step by Step Solution

  1. Step 1: Write the proportion equation
    30.47 : 42 = 18.18 : x
  2. Step 2: Convert to fraction form
    30.47/42 = 18.18/x
  3. Step 3: Cross multiply
    30.47x = 42 × 18.18
  4. Step 4: Simplify right side
    30.47x = 763.56
  5. Step 5: Solve for x
    x = 763.56/30.47
  6. Step 6: Final answer
    x = 25.06

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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.