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Finding the Fourth Proportional to 810.84, 1,214.67 and 421.10

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Solution

The fourth proportional to 810.84, 1,214.67 and 421.10 is: 630.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    810.84 : 1,214.67 = 421.10 : x
  2. Step 2: Convert to fraction form
    810.84/1,214.67 = 421.10/x
  3. Step 3: Cross multiply
    810.84x = 1,214.67 × 421.10
  4. Step 4: Simplify right side
    810.84x = 511,497.54
  5. Step 5: Solve for x
    x = 511,497.54/810.84
  6. Step 6: Final answer
    x = 630.82

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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.