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Finding the Fourth Proportional to 645.51, 891.04 and 393.46

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Solution

The fourth proportional to 645.51, 891.04 and 393.46 is: 543.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    645.51 : 891.04 = 393.46 : x
  2. Step 2: Convert to fraction form
    645.51/891.04 = 393.46/x
  3. Step 3: Cross multiply
    645.51x = 891.04 × 393.46
  4. Step 4: Simplify right side
    645.51x = 350,588.60
  5. Step 5: Solve for x
    x = 350,588.60/645.51
  6. Step 6: Final answer
    x = 543.12

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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.