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Finding the Fourth Proportional to 810.90, 1,216.36 and 538.70

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Solution

The fourth proportional to 810.90, 1,216.36 and 538.70 is: 808.06

Step by Step Solution

  1. Step 1: Write the proportion equation
    810.90 : 1,216.36 = 538.70 : x
  2. Step 2: Convert to fraction form
    810.90/1,216.36 = 538.70/x
  3. Step 3: Cross multiply
    810.90x = 1,216.36 × 538.70
  4. Step 4: Simplify right side
    810.90x = 655,253.13
  5. Step 5: Solve for x
    x = 655,253.13/810.90
  6. Step 6: Final answer
    x = 808.06

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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.