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Finding the Fourth Proportional to 810.12, 1,215.45 and 290.02

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Solution

The fourth proportional to 810.12, 1,215.45 and 290.02 is: 435.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    810.12 : 1,215.45 = 290.02 : x
  2. Step 2: Convert to fraction form
    810.12/1,215.45 = 290.02/x
  3. Step 3: Cross multiply
    810.12x = 1,215.45 × 290.02
  4. Step 4: Simplify right side
    810.12x = 352,497.28
  5. Step 5: Solve for x
    x = 352,497.28/810.12
  6. Step 6: Final answer
    x = 435.12

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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.