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Finding the Fourth Proportional to 811.33, 1,217 and 378.25

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Solution

The fourth proportional to 811.33, 1,217 and 378.25 is: 567.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    811.33 : 1,217 = 378.25 : x
  2. Step 2: Convert to fraction form
    811.33/1,217 = 378.25/x
  3. Step 3: Cross multiply
    811.33x = 1,217 × 378.25
  4. Step 4: Simplify right side
    811.33x = 460,330.25
  5. Step 5: Solve for x
    x = 460,330.25/811.33
  6. Step 6: Final answer
    x = 567.38

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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.