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Finding the Fourth Proportional to 810.08, 1,215.20 and 290.12

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Solution

The fourth proportional to 810.08, 1,215.20 and 290.12 is: 435.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    810.08 : 1,215.20 = 290.12 : x
  2. Step 2: Convert to fraction form
    810.08/1,215.20 = 290.12/x
  3. Step 3: Cross multiply
    810.08x = 1,215.20 × 290.12
  4. Step 4: Simplify right side
    810.08x = 352,555.41
  5. Step 5: Solve for x
    x = 352,555.41/810.08
  6. Step 6: Final answer
    x = 435.21

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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.