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Finding the Fourth Proportional to 405.80, 559.66 and 289.16

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Solution

The fourth proportional to 405.80, 559.66 and 289.16 is: 398.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    405.80 : 559.66 = 289.16 : x
  2. Step 2: Convert to fraction form
    405.80/559.66 = 289.16/x
  3. Step 3: Cross multiply
    405.80x = 559.66 × 289.16
  4. Step 4: Simplify right side
    405.80x = 161,831.29
  5. Step 5: Solve for x
    x = 161,831.29/405.80
  6. Step 6: Final answer
    x = 398.80

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.