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Finding the Fourth Proportional to 6.45, 8.90 and 5.65

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Solution

The fourth proportional to 6.45, 8.90 and 5.65 is: 7.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    6.45 : 8.90 = 5.65 : x
  2. Step 2: Convert to fraction form
    6.45/8.90 = 5.65/x
  3. Step 3: Cross multiply
    6.45x = 8.90 × 5.65
  4. Step 4: Simplify right side
    6.45x = 50.29
  5. Step 5: Solve for x
    x = 50.29/6.45
  6. Step 6: Final answer
    x = 7.80

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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.