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Finding the Fourth Proportional to 811.08, 1,216.80 and 378

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Solution

The fourth proportional to 811.08, 1,216.80 and 378 is: 567.08

Step by Step Solution

  1. Step 1: Write the proportion equation
    811.08 : 1,216.80 = 378 : x
  2. Step 2: Convert to fraction form
    811.08/1,216.80 = 378/x
  3. Step 3: Cross multiply
    811.08x = 1,216.80 × 378
  4. Step 4: Simplify right side
    811.08x = 459,950.40
  5. Step 5: Solve for x
    x = 459,950.40/811.08
  6. Step 6: Final answer
    x = 567.08

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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.