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Finding the Fourth Proportional to 387.85, 581.85 and 319.65

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Solution

The fourth proportional to 387.85, 581.85 and 319.65 is: 479.53

Step by Step Solution

  1. Step 1: Write the proportion equation
    387.85 : 581.85 = 319.65 : x
  2. Step 2: Convert to fraction form
    387.85/581.85 = 319.65/x
  3. Step 3: Cross multiply
    387.85x = 581.85 × 319.65
  4. Step 4: Simplify right side
    387.85x = 185,986.75
  5. Step 5: Solve for x
    x = 185,986.75/387.85
  6. Step 6: Final answer
    x = 479.53

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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.