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Finding the Fourth Proportional to 393, 542.10 and 315.56

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Solution

The fourth proportional to 393, 542.10 and 315.56 is: 435.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    393 : 542.10 = 315.56 : x
  2. Step 2: Convert to fraction form
    393/542.10 = 315.56/x
  3. Step 3: Cross multiply
    393x = 542.10 × 315.56
  4. Step 4: Simplify right side
    393x = 171,065.08
  5. Step 5: Solve for x
    x = 171,065.08/393
  6. Step 6: Final answer
    x = 435.28

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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.