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Finding the Fourth Proportional to 810.18, 1,215.40 and 290.06

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Solution

The fourth proportional to 810.18, 1,215.40 and 290.06 is: 435.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    810.18 : 1,215.40 = 290.06 : x
  2. Step 2: Convert to fraction form
    810.18/1,215.40 = 290.06/x
  3. Step 3: Cross multiply
    810.18x = 1,215.40 × 290.06
  4. Step 4: Simplify right side
    810.18x = 352,532.85
  5. Step 5: Solve for x
    x = 352,532.85/810.18
  6. Step 6: Final answer
    x = 435.13

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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.