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Finding the Third Proportional to 420.19 and 751.78

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Solution

The third proportional to 420.19 and 751.78 is: 1,345.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.19 : 751.78 = 751.78 : x
  2. Step 2: Convert to fraction form
    420.19/751.78 = 751.78/x
  3. Step 3: Cross multiply
    420.19x = 751.78 × 751.78
  4. Step 4: Simplify right side
    420.19x = 565,175.05
  5. Step 5: Solve for x
    x = 565,175.05/420.19
  6. Step 6: Final answer
    x = 1,345.05

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Why These Related Problems?

These problems maintain the same ratio (1.79) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.