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Finding the Fourth Proportional to 810.86, 1,215.84 and 290.84

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Solution

The fourth proportional to 810.86, 1,215.84 and 290.84 is: 436.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    810.86 : 1,215.84 = 290.84 : x
  2. Step 2: Convert to fraction form
    810.86/1,215.84 = 290.84/x
  3. Step 3: Cross multiply
    810.86x = 1,215.84 × 290.84
  4. Step 4: Simplify right side
    810.86x = 353,614.91
  5. Step 5: Solve for x
    x = 353,614.91/810.86
  6. Step 6: Final answer
    x = 436.10

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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.