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Finding the Fourth Proportional to 9, 12.40 and 6.69

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Solution

The fourth proportional to 9, 12.40 and 6.69 is: 9.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    9 : 12.40 = 6.69 : x
  2. Step 2: Convert to fraction form
    9/12.40 = 6.69/x
  3. Step 3: Cross multiply
    9x = 12.40 × 6.69
  4. Step 4: Simplify right side
    9x = 82.96
  5. Step 5: Solve for x
    x = 82.96/9
  6. Step 6: Final answer
    x = 9.22

Related Problems

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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.