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Finding the Fourth Proportional to 30.89, 42.64 and 18.60

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Solution

The fourth proportional to 30.89, 42.64 and 18.60 is: 25.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    30.89 : 42.64 = 18.60 : x
  2. Step 2: Convert to fraction form
    30.89/42.64 = 18.60/x
  3. Step 3: Cross multiply
    30.89x = 42.64 × 18.60
  4. Step 4: Simplify right side
    30.89x = 793.10
  5. Step 5: Solve for x
    x = 793.10/30.89
  6. Step 6: Final answer
    x = 25.68

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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.