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Finding the Fourth Proportional to 810.25, 1,215.71 and 485.44

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Solution

The fourth proportional to 810.25, 1,215.71 and 485.44 is: 728.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    810.25 : 1,215.71 = 485.44 : x
  2. Step 2: Convert to fraction form
    810.25/1,215.71 = 485.44/x
  3. Step 3: Cross multiply
    810.25x = 1,215.71 × 485.44
  4. Step 4: Simplify right side
    810.25x = 590,150.62
  5. Step 5: Solve for x
    x = 590,150.62/810.25
  6. Step 6: Final answer
    x = 728.36

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1.5x scale

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.