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Finding the Fourth Proportional to 810.58, 1,214.65 and 485.59

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Solution

The fourth proportional to 810.58, 1,214.65 and 485.59 is: 727.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    810.58 : 1,214.65 = 485.59 : x
  2. Step 2: Convert to fraction form
    810.58/1,214.65 = 485.59/x
  3. Step 3: Cross multiply
    810.58x = 1,214.65 × 485.59
  4. Step 4: Simplify right side
    810.58x = 589,819.46
  5. Step 5: Solve for x
    x = 589,819.46/810.58
  6. Step 6: Final answer
    x = 727.65

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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.