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Finding the Fourth Proportional to 805.16, 1,207.80 and 285.08

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Solution

The fourth proportional to 805.16, 1,207.80 and 285.08 is: 427.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    805.16 : 1,207.80 = 285.08 : x
  2. Step 2: Convert to fraction form
    805.16/1,207.80 = 285.08/x
  3. Step 3: Cross multiply
    805.16x = 1,207.80 × 285.08
  4. Step 4: Simplify right side
    805.16x = 344,319.62
  5. Step 5: Solve for x
    x = 344,319.62/805.16
  6. Step 6: Final answer
    x = 427.64

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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.