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Finding the Fourth Proportional to 30.15, 45 and 28.67

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Solution

The fourth proportional to 30.15, 45 and 28.67 is: 42.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    30.15 : 45 = 28.67 : x
  2. Step 2: Convert to fraction form
    30.15/45 = 28.67/x
  3. Step 3: Cross multiply
    30.15x = 45 × 28.67
  4. Step 4: Simplify right side
    30.15x = 1,289.93
  5. Step 5: Solve for x
    x = 1,289.93/30.15
  6. Step 6: Final answer
    x = 42.78

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.