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Finding the Fourth Proportional to 397.76, 549.28 and 315.20

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Solution

The fourth proportional to 397.76, 549.28 and 315.20 is: 435.27

Step by Step Solution

  1. Step 1: Write the proportion equation
    397.76 : 549.28 = 315.20 : x
  2. Step 2: Convert to fraction form
    397.76/549.28 = 315.20/x
  3. Step 3: Cross multiply
    397.76x = 549.28 × 315.20
  4. Step 4: Simplify right side
    397.76x = 173,133.06
  5. Step 5: Solve for x
    x = 173,133.06/397.76
  6. Step 6: Final answer
    x = 435.27

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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.