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Finding the Fourth Proportional to 5.40, 8.05 and 5.15

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Solution

The fourth proportional to 5.40, 8.05 and 5.15 is: 7.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    5.40 : 8.05 = 5.15 : x
  2. Step 2: Convert to fraction form
    5.40/8.05 = 5.15/x
  3. Step 3: Cross multiply
    5.40x = 8.05 × 5.15
  4. Step 4: Simplify right side
    5.40x = 41.43
  5. Step 5: Solve for x
    x = 41.43/5.40
  6. Step 6: Final answer
    x = 7.67

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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.