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Finding the Fourth Proportional to 318.99, 478.65 and 145.74

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Solution

The fourth proportional to 318.99, 478.65 and 145.74 is: 218.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    318.99 : 478.65 = 145.74 : x
  2. Step 2: Convert to fraction form
    318.99/478.65 = 145.74/x
  3. Step 3: Cross multiply
    318.99x = 478.65 × 145.74
  4. Step 4: Simplify right side
    318.99x = 69,758.45
  5. Step 5: Solve for x
    x = 69,758.45/318.99
  6. Step 6: Final answer
    x = 218.69

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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.