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Finding the Fourth Proportional to 813.16, 1,218.88 and 401.78

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Solution

The fourth proportional to 813.16, 1,218.88 and 401.78 is: 602.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    813.16 : 1,218.88 = 401.78 : x
  2. Step 2: Convert to fraction form
    813.16/1,218.88 = 401.78/x
  3. Step 3: Cross multiply
    813.16x = 1,218.88 × 401.78
  4. Step 4: Simplify right side
    813.16x = 489,725.16
  5. Step 5: Solve for x
    x = 489,725.16/813.16
  6. Step 6: Final answer
    x = 602.25

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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.