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Finding the Fourth Proportional to 810.74, 1,216.31 and 290.80

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Solution

The fourth proportional to 810.74, 1,216.31 and 290.80 is: 436.27

Step by Step Solution

  1. Step 1: Write the proportion equation
    810.74 : 1,216.31 = 290.80 : x
  2. Step 2: Convert to fraction form
    810.74/1,216.31 = 290.80/x
  3. Step 3: Cross multiply
    810.74x = 1,216.31 × 290.80
  4. Step 4: Simplify right side
    810.74x = 353,703.01
  5. Step 5: Solve for x
    x = 353,703.01/810.74
  6. Step 6: Final answer
    x = 436.27

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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.