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Finding the Fourth Proportional to 810.77, 1,214.93 and 485.78

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Solution

The fourth proportional to 810.77, 1,214.93 and 485.78 is: 727.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    810.77 : 1,214.93 = 485.78 : x
  2. Step 2: Convert to fraction form
    810.77/1,214.93 = 485.78/x
  3. Step 3: Cross multiply
    810.77x = 1,214.93 × 485.78
  4. Step 4: Simplify right side
    810.77x = 590,183.84
  5. Step 5: Solve for x
    x = 590,183.84/810.77
  6. Step 6: Final answer
    x = 727.93

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.