Home / 645.15-890.35-393.18

Finding the Fourth Proportional to 645.15, 890.35 and 393.18

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Solution

The fourth proportional to 645.15, 890.35 and 393.18 is: 542.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    645.15 : 890.35 = 393.18 : x
  2. Step 2: Convert to fraction form
    645.15/890.35 = 393.18/x
  3. Step 3: Cross multiply
    645.15x = 890.35 × 393.18
  4. Step 4: Simplify right side
    645.15x = 350,067.81
  5. Step 5: Solve for x
    x = 350,067.81/645.15
  6. Step 6: Final answer
    x = 542.61

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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.