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Finding the Fourth Proportional to 405.48, 558.81 and 318

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Solution

The fourth proportional to 405.48, 558.81 and 318 is: 438.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    405.48 : 558.81 = 318 : x
  2. Step 2: Convert to fraction form
    405.48/558.81 = 318/x
  3. Step 3: Cross multiply
    405.48x = 558.81 × 318
  4. Step 4: Simplify right side
    405.48x = 177,701.58
  5. Step 5: Solve for x
    x = 177,701.58/405.48
  6. Step 6: Final answer
    x = 438.25

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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.