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Finding the Fourth Proportional to 76.09, 105 and 45

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Solution

The fourth proportional to 76.09, 105 and 45 is: 62.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    76.09 : 105 = 45 : x
  2. Step 2: Convert to fraction form
    76.09/105 = 45/x
  3. Step 3: Cross multiply
    76.09x = 105 × 45
  4. Step 4: Simplify right side
    76.09x = 4,725
  5. Step 5: Solve for x
    x = 4,725/76.09
  6. Step 6: Final answer
    x = 62.10

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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.